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Eye disease in an onchocerciasis-endemic area of the forest-savanna mosaic region of Nigeria.

In a forest-saving mosaic zone of south-eastern Nigeria endemic for onchocerciasis, we identified eye disorders in 65.5% of a randomly selected population sample. Onchocerciasis-related eye disease was present in 13.7% of the study sample and constituted 21% of the total number of eye disorders. A total of 78 (33.2%) of 235 subjects with visual impairment had onchocerciasis-related eye lesions, and of 35 who were blind in both eyes, onchocerciasis-induced eye disease was the cause in 28 (80%). The prevalence of bilateral blindness from all causes in the study area was 4.1%, while that from onchocerciasis-related causes was 3.3%. The commonest onchocerciasis-induced lesions that were responsible for visual impairment and blindness were choroidoretinitis and optic nerve disease. Sclerosing keratitis, an important causative lesion in onchocerciasis-endemic savanna regions, was encountered only one. Eye disease is therefore an important feature of onchocerciasis in the forest-savanna mosaic areas of Nigeria and should be borne in mind when planning and executing control programmes.

Adolescent

Genetic variation in Asiatic lions and Indian tigers.

Previous reports have suggested that Asiatic lions and tigers are highly inbred and exhibit very low levels of genetic variation. Our analyses on these species have shown much higher degrees of polymorphism than reported. Randomly amplified polymorphic DNA (RAPD) analysis of 38 Asiatic lions, which exist as a single population in the Gir Forest Sanctuary in India, shows an average heterozygosity of 25.82% with four primers. Sperm motility studies by our colleagues corroborate this data. In Indian tigers, microsatellite analysis of five CA repeat loci and multilocus fingerprinting using Bkm 2(8) probe on a population of 22 individuals revealed a heterozygosity of 22.65%. Microsatellite analysis of loci Fca 77 and Fca 126 revealed polymorphism amongst the Asiatic x African lion hybrids, which has enabled us to use these as markers to discriminate the pure Asiatic lions from the hybrids. A similar analysis was used to identify hybrids of Indian and Siberian tigers through polymerase chain reaction (PCR) amplification of hair samples. To ascertain the variation which existed before the population bottleneck at the turn of the present century, microsatellite analysis was performed on 50- to 125-year-old skin samples from museum specimens. Our results show similar levels of genetic variability as in the present population (21.01%). This suggests that low genetic variability may be the characteristic feature of these species and not the result of intensive inbreeding. DNA fingerprinting studies of Asiatic lions and tigers have helped in identifying individuals with high genetic variability which can be used for conservation breeding programs.

Animals

Risk factors associated with alterations in carotid intima-media thickness in hypertension: baseline data from the European Lacidipine Study on Atherosclerosis.

BACKGROUND: The possibility that calcium antagonists exert an anti-atherosclerotic action at least partly independently of the blood-pressure-lowering effect is supported by results of a large number of experimental studies and can now be investigated by quantitative B-mode ultrasound imagining of the carotid artery walls. DESIGN: The European Lacidipine Study on Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multinational trial comparing effects of 4-year treatment based on the long-acting, highly lipophilic calcium antagonist lacidipine with those of treatment based on the beta-blocker atenolol on the development of carotid artery wall alterations in patients (aged 45-75 years) with mild-to-moderate hypertension (systolic blood pressure 150-210 mmHg and diastolic blood pressure 95-115 mmHg). While the intervention study is progressing, this article summarizes baseline data obtained from the whole cohort of 2259 patients randomly allocated to treatment. METHODS: Baseline ultrasound data were obtained from two replicate examinations performed shortly before random allocation to treatment by certified sonographers at 23 referral centres and read at the ultrasound coordinating centre at the Wake Forest University School of Medicine. Intima-media thickness was measured at up to 12 different sites in the carotid artery tree and expressed as the mean of the maxima at these sites (Mmax), the mean of the maxima at four sites in the distal common carotid artery and bifurcation (CBMmax) and the maximum intima-media thickness (Tmax). Baseline demographic and clinical measurements were performed by investigators in 410 peripheral clinical units and 24 h ambulatory blood pressure monitorings read and validated by members of a centralized unit at the University of Milan. The statistical analysis centre at the Technische Universität München received and analysed all baseline data, by calculating means +/- SD, medians and ranges and performing correlation (Spearman correlation coefficients) and multiple regression analyses. RESULTS: Prevalence of carotid artery wall alterations among the hypertensive patients randomly allocated to treatment in the ELSA was very high: 82% had Tmax > or = 1.3 mm ('plaques' according to protocol) and 17% had Tmax > or = 1.0 and < 1.3 mm ('thickening'), with a median of two plaques per patient. We found significant correlations between ultrasound measurements and the following demographic and clinical variables: age, sex, systolic blood pressure and pulse pressure (both clinic and ambulatory), concentrations of total, high-density lipoprotein and low-density lipoprotein cholesterol and triglycerides, smoking habit and duration of hypertension. We found no significant correlation to diastolic blood pressure and glucose concentration. A multiple regression analysis indicated significant variables in the following rank order: age, 24 h ambulatory pulse pressure, sex, low-density lipoprotein cholesterol concentration, triglyceride concentration, smoking and clinic systolic blood pressure. CONCLUSIONS: Analysis of baseline data from the ELSA has shown that there is an extremely marked prevalence of carotid artery wall alterations among mild-to-moderate, middle-aged hypertensive patients. In addition to age, systolic blood pressure and pulse pressure, particularly if they are accurately measured by ambulatory monitoring, play a major role, somewhat greater than those of sex, low-density lipoprotein cholesterol concentration and smoking, in influencing intima-media thickness.

Adrenergic beta-Antagonists

Diagnostic accuracy of bronchoalveolar lavage fluid-based testing for pulmonary cryptococcosis: A systematic review and meta-analysis.

BACKGROUND: Pulmonary cryptococcosis(PC) presents diagnostic challenges because of its non-specific clinical and radiological manifestations. Bronchoalveolar lavage fluid (BALF)-based testing, which includes latex agglutination (LA) and lateral flow assay (LFA), offers a minimally invasive diagnostic method, yet its pooled diagnostic accuracy remains unclear. METHODS: We systematically searched PubMed, Embase, Cochrane Library, and Scopus from inception to May 2026. Studies evaluating BALF-based testing for PC with extractable 2 &#xd7; 2 data were included. The methodological quality of relevant studies was assessed by the QUADAS-2 tool. Pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratio (DOR) were estimated using a bivariate random-effects model. Subgroup analyses were performed by testing method and reference standard type. Heterogeneity was evaluated through paired forest plots, HSROC visualization, and exploratory bivariate meta-regression. RESULTS: The pooled sensitivity was 0.87 (95% CI: 0.81-0.91), and the specificity was 0.99 (95% CI: 0.982 - 0.995). The pooled positive likelihood ratio (PLR) was 88.00 (95% CI: 47.39 - 163.42), the negative likelihood ratio (NLR) was 0.13 (95% CI: 0.09 -0.20), and the DOR was 658.50 (95% CI: 285.36-1519.55). No significant threshold effect or publication bias was detected. Exploratory meta-regression suggested a possible assay-method effect in the joint model (P = 0.03), mainly driven by specificity (P = 0.01). CONCLUSIONS: The study demonstrates the high accuracy of CrAg in BALF for the diagnosis of pulmonary cryptococcosis, supporting its role as an important adjunctive diagnostic tool, particularly when tissue biopsy is not feasible or rapid results are needed. Larger prospective studies with standardized protocols are needed to validate these estimates.

Humans

Seasonal incidence and hemoparasite infection rates of Ixodid ticks (Acari: Ixodidae) detached from cattle in Costa Rica.

To determine the tick species hindering the cattle industry in Costa Rica and to assess infection rates of ticks with three important hemoparasite species, cattle were monitored during a period of six months (October 1992-March 1993). Four farms were located in the dry pacific region of the canton of Tilarán and a fifth farm on the slopes of the Poás volcano in a cool tropical cloud-forest ecosystem. On each farm 3 to 5 animals of 6 to 24 months of age were selected at random. All ticks were removed on a monthly basis from the right half side of each animal, while the site of attachment was recorded. Ticks were counted and differentiated according to species, developmental stage and sex. Moreover, engorged female ticks were assayed for the presence of Babesia bigemina, Babesia bovis and Anaplasma marginale using the polymerase chain reaction (PCR) multiplex system. Two species of ticks, Amblyomma cajennense and Boophilus microplus, were encountered on the cattle in the Tilarán region and one species, B. microplus, was detected in the Poás region. Two to ten times as many ticks were encountered in the Tilarán region than in the Poás region, which is in accordance with a stable enzootic protozoan disease situation in the former region and an unstable epizootic situation in the latter region. Nymphal and adult stages of both tick species were present in largest numbers on the ventral parts of the animals. PCR analysis of entire ticks indicated very high infection rates with hemoparasites of veterinary importance. This was in accordance with high seroprevalence rates in the hosts.

Animals

Environmental risk factors for Lyme disease identified with geographic information systems.

OBJECTIVES: A geographic information system was used to identify and locate residential environmental risk factors for Lyme disease. METHODS: Data were obtained for 53 environmental variables at the residences of Lyme disease case patients in Baltimore County from 1989 through 1990 and compared with data for randomly selected addresses. A risk model was generated combining the geographic information system with logistic regression analysis. The model was validated by comparing the distribution of cases in 1991 with another group of randomly selected addresses. RESULTS: In crude analyses, 11 environmental variables were associated with Lyme disease. In adjusted analyses, residence in forested areas (odds ratio [OR] = 3.7, 95% confidence interval [CI] = 1.2, 11.8), on specific soils (OR = 2.1, 95% CI = 1.0, 4.4), and in two regions of the county (OR = 3.5, 95% CI = 1.6, 7.4) (OR = 2.8, 95% CI = 1.0, 7.7) was associated with elevated risk of getting Lyme disease. Residence in highly developed regions was protective (OR = 0.3, 95% CI = 0.1, 1.0). The risk of Lyme disease in 1991 increased with risk categories defined from the 1989 through 1990 data. CONCLUSIONS: Combining a geographic information system with epidemiologic methods can be used to rapidly identify risk factors of zoonotic disease over large areas.

Environmental Exposure

Holmium laser enucleation of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia.

RATIONALE: A range of surgical options is available for the treatment of benign prostatic hyperplasia (BPH), including holmium laser enucleation of the prostate (HoLEP). The evidence is unclear regarding differences in functional, perioperative, and morbidity outcomes between these modalities. OBJECTIVES: To assess the effects of holmium laser enucleation of the prostate compared with other surgical treatments for lower urinary tract symptoms in men with benign prostatic hyperplasia. SEARCH METHODS: We searched multiple databases (including MEDLINE, Embase, CENTRAL, Web of Science, LILACS, and the International HTA database), trial registries, and conference abstracts through April 08, 2026. ELIGIBILITY CRITERIA: We only included randomized trials of men over 40 years of age with a prostate volume of at least 20 mL (assessed by digital rectal examination, ultrasound, or conventional imaging) who exhibited lower urinary tract symptoms (LUTS) defined by an International Prostate Symptom Score (IPSS) of eight or greater undergoing surgical interventions for BPH. OUTCOMES: The critical outcomes measured were the urologic symptoms score, the quality-of-life score, and major adverse events. The important outcomes measured were: re-treatment, erectile function, ejaculatory function, transfusions, acute urinary retention, indwelling urinary catheter duration, and hospital stay duration. RISK OF BIAS: We used the Cochrane risk of bias tool (RoB 1) to assess for potential sources of bias on a study and outcome level basis. SYNTHESIS METHODS: We pooled outcome data using the random-effects model and performed meta-analyses using the Mantel-Haenszel method. We assessed statistical heterogeneity in the pooled data by visually inspecting forest plots and using the I2 statistic to quantify it. We used the GRADE framework to assess the certainty of evidence. INCLUDED STUDIES: We included 52 trials that included 6242 participants that compared HoLEP to other surgical interventions for benign prostatic hyperplasia. The median age of participants across the studies ranged from 65 to 74 years. The baseline prostate volume ranged from 30 cc to 142 cc. Baseline IPSS scores ranged from 19.6 to 28.6 (range 0-35). SYNTHESIS OF RESULTS: We prioritized comparing HoLEP with transurethral resection of the prostate (TURP) at short-term follow-up (up to 12 months), because TURP is the long-standing reference standard and the predominant comparator in randomized surgical trials. Findings for the four remaining comparisons (laser ablation, alternative energy source enucleation, other minimally invasive therapies, and simple prostatectomy), for long-term follow-up, and for all remaining outcomes are reported in full in the review. Compared to TURP, at short-term follow-up: Critical outcomes - HoLEP may result in little to no difference in short-term urologic symptom scores measured using the IPSS (range 0 to 35; lower values reflect fewer symptoms) (MD -0.67, 95% CI -1.20 to -0.14; I&#xb2; = 93%; 14 studies, 1666 participants, low-certainty evidence). - HoLEP may result in little to no difference in short-term quality of life (range 0 to 6; lower values reflect better quality of life) (MD -0.04, 95% CI -0.23 to 0.15; I&#xb2; = 73%; 6 studies, 876 participants, low-certainty evidence). - HoLEP may result in little to no difference in short-term major adverse events (RR 0.75, 95% CI 0.35 to 1.58; I&#xb2; = 0%; 10 studies, 1147 participants, low-certainty evidence). Important outcomes - HoLEP likely results in little to no difference in re-treatment (RR 0.45, 95% CI 0.14 to 1.50; I&#xb2; = 0%; 8 studies, 813 participants, moderate-certainty evidence). - HoLEP likely results in little to no difference in erectile function (MD -0.03, 95% CI -0.47 to 0.42; I&#xb2; = 0%; 3 studies, 518 participants, moderate-certainty evidence). - Ejaculatory function: we did not find any data for this outcome. - HoLEP likely reduces the need for blood transfusion (RR 0.19, 95% CI 0.09 to 0.42; I&#xb2; = 0%; 15 studies, 1755 participants, moderate-certainty evidence). AUTHORS' CONCLUSIONS: Compared with TURP, HoLEP may achieve similar relief of urologic symptoms, similar quality of life, and similar rates of major adverse events in the first 12 months after surgery, and probably similar re-treatment rates and erectile function. HoLEP likely reduces the need for blood transfusion; this is the only advantage of HoLEP that the randomized evidence, as summarized here, supports as clinically important. There was insufficient evidence to assess outcomes in the subset of individuals with larger prostates or on anticoagulation. Future research should prioritize long-term trials reporting sexual function and urinary incontinence outcomes, recruit men with very large prostates (&#x2265; 150 cc) or on anticoagulation therapy, and evaluate cost-effectiveness and training requirements. FUNDING: No external funding was received for this review. REGISTRATION: The protocol for this review was published in the Cochrane Database 2019 (https://doi.org/10.1002/14651858.CD013291).

Humans

Effects of transcutaneous electrical acupoint stimulation versus acupressure on the trajectories of multidimensional adverse reactions to chemotherapy in breast cancer patients: a secondary analysis of a randomized controlled trial.

BACKGROUND: Chemotherapy for breast cancer often induces multidimensional adverse reactions such as nausea and vomiting, anxiety, depression, and sleep disturbances. These symptoms are interrelated and may evolve dynamically, impacting patients' treatment outcomes and quality of life. As non-pharmacological interventions, transcutaneous electrical acupoint stimulation (TEAS) and self-acupressure (SA) have shown potential in alleviating symptoms. However, their long-term effects on the joint developmental trajectories of these multidimensional symptoms (nausea and vomiting, anxiety, depression, and sleep disturbances) remain unclear. OBJECTIVE: This study aimed to identify potential trajectory class of multidimensional adverse reactions in breast cancer patients undergoing chemotherapy and to explore the differential effects of TEAS and SA on different trajectory subgroups. METHODS: This was a secondary analysis of a randomized controlled trial. A total of 189 breast cancer patients receiving chemotherapy were included. The Group-Based Multi-Trajectory Model (GBMTM) was employed to identify joint developmental trajectories of acute/delayed chemotherapy-induced nausea and vomiting (CINV), anxiety, depression, and sleep quality during chemotherapy. Subsequently, causal forest was used to analyze the average treatment effects (ATE) of TEAS (vs. control group) and SA (vs. control group) on patients' symptom trajectory. RESULTS: Multidimensional adverse reactions were classified into two heterogeneous trajectories: a "High Symptom Burden-Persistent (HSBP)" type (n&#x2009;=&#x2009;101) and a "Low Symptom Burden-Relieving (LSBR)" type (n&#x2009;=&#x2009;88). The persistent high incidence of acute CINV contrasted sharply with the comprehensive relief of other symptoms in the latter group. Causal forest suggested that both TEAS and SA significantly increased the probability of patients being classified into the "LSBR" trajectory. The ATE was 0.147 (95% CI: 0.143, 0.151) for TEAS, slightly lower (P&#x2009;<&#x2009;0.05) than 0.176 (95% CI: 0.162, 0.190) for SA.&#xa0; CONCLUSION: Multidimensional adverse reactions in breast cancer patients undergoing chemotherapy exhibit heterogeneity in their trajectories. Both TEAS and SA were associated with a higher probability of patients being classified into a more favorable symptom trajectory-LSBR. The multidimensional trajectory identification with treatment effect estimation may serve as a useful analytical strategy for future longitudinal research in cancer chemotherapy-induced adverse reactions symptom management. CLINICAL TRIAL REGISTRATION: ChiCTR2300077667 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/ ), Registered 15 November 2023.

Humans

Regional Representativeness of Swedish Reference Lakes.

/ Recent focus has been placed on ecoregion delineations for providing an appropriate framework for monitoring and assessment of region-specific attainable water/habitat quality. Using an ecoregion approach to stratify variance, this study was conducted to determine whether earlier (subjectively) selected Swedish reference lakes may be considered as regionally representative reference sites when compared with a randomly selected lake population. Predictive modeling by discriminant function analysis with lakes classified by ecoregion and lake surface area and six physicochemical variables showed that the greater majority of reference lakes may be considered as regionally representative. The highest proportion of lake "misclassifications" occurred in the boreonemoral ecoregion, a relatively diverse ecoregion of southern Sweden. This apparent bias may be in part be due to the criteria used in selecting regional reference lakes. In the earlier selection of reference lakes emphasis was placed on lakes not being adversely affected by land usage or pollutant discharges, consequently forest lakes were often overrepresented and sites in agricultural areas underrepresented in the selected reference sites. As a complement to predictive modeling, PCA ordination showed the placement of reference lakes within the random lake population and indicated where reference sites might be missing along potentially important ecological gradients. KEY WORDS: Regionalization; Ecoregion; Representativeness; Reference; Ordination; Modeling; Temperate lakes

Journal Article

Red howling monkey use of specific defecation sites as a parasite avoidance strategy

Red howling monkeys, Alouatta seniculusin the central Amazonian basin move to specific sites before defecating. Differences in the vegetation profile of behavioural sites, defecation sites and random sites within the ranging area of howler groups were examined. The defecation sites used differed in the number of leaf intercepts at the levels of the forest the monkeys used for foraging and travelling. Defecating in areas free of underlying vegetation decreases the likelihood of contaminating potential food sources or arboreal pathways. This defecation behaviour may be an important parasite avoidance strategy of red howling monkeys.

Journal Article

Evaluation of SPf66 malaria vaccine during a 22-month follow-up field trial in the Pacific coast of Colombia.

A double-blind randomized placebo-controlled field trial with the SPf66 malaria vaccine was carried out in an endemic area consisting of 14 small villages with exclusive fluvial access, in a rain forest area along the Rosario River, Colombia. A total of 1257 subjects completed the full three dose vaccination schedule on days 0, 30 and 180 (643 vaccinated group/623 placebo group) and were followed-up by passive and active surveillance over a period of 22 months. One hundred and thirty-four Plasmodium falciparum malaria episodes were detected (53 in vaccinated group/81 in placebo group), yielding an attack rate of 5.47 cases/100 person years of follow-up (pyears) in the vaccine group and 8.44/100 pyears in the placebo group. The estimated vaccine protective efficacy was 35.2% (95% CI 8.4-54.2%, P = 0.01). This result supports earlier findings that the SPf66 malaria vaccine diminishes the risk of infection by P. falciparum in endemic areas of South America.

Adolescent

Deltamethrin impregnated bednets for the control of urban malaria in Kumba Town, South-West Province of Cameroon.

This study was conducted from January to December 1992 in Kumba, a town situated in the rain forest region of the South-West Province of Cameroon, and consisted of a longitudinal survey including parasitological and clinical studies. Forty households were chosen for the study and randomly divided into two groups, each with approximately 240 inhabitants aged < or = 15 years. One group received deltamethrin impregnated bednets and the other group had no nets (control). For the months of April, June and August (rainy season), deltamethrin impregnated bednets did not reduce malaria prevalence significantly, but the overall malaria prevalence for all months of the study was significantly reduced (chi 2 MH = 9.17, P = 0.002). Enlarged spleen rates (chi 2 MH = 6.73, P = 0.009) and spleen sizes (P = 0.0002) were also significantly reduced by the nets. However, the reduction in the geometric mean parasite density (GMPD) was not significant. Even though some of these reductions were statistically significant, they were relatively low in a global context compared with previous work done mainly in rural areas. In an urban environment, parents and children usually stay up late, and probably receive many mosquito bites before going to sleep.

Adolescent

Incidence of localized cutaneous leishmaniasis (chiclero's ulcer) in Mexico.

Cutaneous leishmaniasis in Mexico was first described in 1912. Since then, its existence has been repeatedly confirmed in the forest regions of the peninsula of Yucatan. In order to obtain reliable knowledge about the magnitude of this problem, we questioned and skin-tested a sample of 449 persons randomly selected from men aged 15-45 years. We found a positivity rate of 24 to 90% (mean 43%) in the seven rural health posts studied. Furthermore, 72 patients were examined between January and December 1987 by parasitological investigation (smear, isolation, culture and/or biopsy) and the Montenegro skin test; 56 had acquired the disease in 1987. Based on these data, we found an annual incidence rate of 508 per 100,000 inhabitants. Further long-term studies are indicated to determine the incidence and prevalence rates for this disease in other parts of the country.

Adolescent

[Seroepidemiological studies of the detection of leptospires of the sejroe group in cattle in middle Thuringia].

From 1983 to 1989 14,361 head of cattle from the middle Thuringia region were investigated by means of microagglutination test for the presence of Leptospira serovars hardjo, saxkoebing and sejroe. 4,484 samples from cattle with abortion (1983-1985) and a random sample of 5,284 cattle sera (1985) were investigated giving priority to L. hardjo. Furthermore 3,293 samples from cattle with abortion (1986/87) and a random samples test of 1,300 cattle sera (1989) were tested giving priority to L. saxkoebing. 2.5 percent of the cows having aborted and 10.3 percent of cattle tested out of the whole livestock showed antibodies against L. hardjo. The test for presence of L. saxkoebing demonstrated in cattle with abortion a seroprevalence of 14 percent and in the random samples tests a portion of reagents of 11.3 percent. The degree of infection differed regionally, the highest degree was found in livestocks of the northern part of the Thuringia forest. The prevalence of L. saxkoebing in cattle with abortion from large dairy farms was 18.6 percent, which is higher than the average in the region examined. Antibodies against hardjo and sejroe were interpreted as caused by cross reactivity.

Abortion, Veterinary

Directed seed dispersal by bellbirds in a tropical cloud forest.

A fundamental goal of plant population ecology is to understand the consequences for plant fitness of seed dispersal by animals. Theories of seed dispersal and tropical forest regeneration suggest that the advantages of seed dispersal for most plants are escape from seed predation near the parent tree and colonization of vacant sites, the locations of which are unpredictable in space and time. Some plants may gain in fitness as a fortuitous consequence of disperser behavior if certain species of dispersers nonrandomly place seeds in sites predictably favorable for seedling establishment. Such patterns of directed dispersal by vertebrates long have been suggested but never demonstrated for tropical forest trees. Here we report the pattern of seed distribution and 1-year seedling survival generated by five species of birds for a neotropical, shade-tolerant tree. Four of the species dispersed seeds to sites near the parent trees with microhabitat characteristics similar to those at random locations, whereas the fifth species, a bellbird, predictably dispersed seeds under song perches in canopy gaps. The pattern of seedling recruitment was bimodal, with a peak near parent trees and a second peak, corresponding to bellbird song perches, far (>40 m) from parent trees. Seedling survival was higher for seeds dispersed by bellbirds than by the other species, because of a reduction in seedling mortality by fungal pathogens in gaps. Thus, bellbirds play a significant role in seed dispersal by providing directed dispersal to favorable sites and therefore may influence plant recruitment patterns and species diversity in Neotropical forests.

Journal Article

A comparative study of culturally transmitted patterns of feeding habits in the chacma baboon Papio ursinus and the vervet monkey Cercopithecus aethiops.

Japanese workers have studied social acquisition patterns of new feeding habits in Macaca fuscata which they have termed precultural. The present study investigates the same phenomenon in the chacma baboon and the vervet monkey in their natural habitat. The questions addressed are: (1) How a new feeding habit enters a troop and by which age and sex category, also how it is propagated? (2) When individuals are permitted with a choice between palatable and unpalatable food, can they learn by demonstration only or do they have to pass through a direct learning process? (3) Can the results from the above questions be explained by social parameters such as the social structure of the individual species? It was found that juvenile baboons discover new food and that after the discovery propagation is instantaneous. In vervets discovery is random among the age classes and propagation is slow and takes place through certain 'pivot' individuals. Both species fail to learn about palatability by demonstration but have to go through a direct learning process. This contrasts strongly with the forest baboon Mandrillus sphinx that have been shown to learn by demonstration. Socially, baboon juveniles stay closer to each other than the adults who force them to live at the periphery of the troop. Vervets again forage without precise sub-group formation. The link between social and cultural propagation and social structure is discussed on the basis of these findings.

Animals

Towards second-generation STS (sequence-tagged sites) linkage maps in conifers: a genetic map of Norway spruce (Picea abies K.).

Genetic linkage maps have been produced for a wide range of organisms during the last decade, thanks to the increasing availability of molecular markers. The use of microsatellites (or Simple Sequence Repeats, SSRs) as genetic markers has led to the construction of "second-generation" genetic maps for humans, mouse and other organisms of major importance. We constructed a second-generation single-tree genetic linkage map of Norway spruce (Picea abies K.) using a panel of 72 haploid megagametophytes with a total of 447 segregating bands [366 Amplified Fragment Length Polymorphisms (AFLPs), 20 Selective Amplification of Microsatellite Polymorphic Loci (SAMPLs) and 61 SSRs, each single band being treated initially as a dominant marker]. Four hundred and thirteen markers were mapped in 29 linkage groups (including triplets and doublets) covering a genetic length of 2198.3 cM, which represents 77.4% of the estimated genome length of Picea abies (approximately 2839 cM). The map is still far from coalescing into the expected 12 chromosomal linkage groups of Norway spruce (2n = 2x = 24). A possible explanation for this comes from the observed non-random distribution of markers in the framework map. Thirty-eight SSR marker loci could be mapped onto 19 linkage groups. This set of highly informative Sequence Tagged Sites (STSs) can be used in many aspects of genetic analysis of forest trees, such as marker-assisted selection, QTL mapping, positional cloning, gene flow analysis, mating system analysis and genetic diversity studies.

Chromosome Mapping