Extent and ecological consequences of hunting in Central African rainforests in the twenty-first century.

Humans have hunted wildlife in Central Africa for millennia. Today, however, many species are being rapidly extirpated and sanctuaries for wildlife are dwindling. Almost all Central Africa's forests are now accessible to hunters. Drastic declines of large mammals have been caused in the past 20 years by the commercial trade for meat or ivory. We review a growing body of empirical data which shows that trophic webs are significantly disrupted in the region, with knock-on effects for other ecological functions, including seed dispersal and forest regeneration. Plausible scenarios for land-use change indicate that increasing extraction pressure on Central African forests is likely to usher in new worker populations and to intensify the hunting impacts and trophic cascade disruption already in progress, unless serious efforts are made for hunting regulation. The profound ecological changes initiated by hunting will not mitigate and may even exacerbate the predicted effects of climate change for the region. We hypothesize that, in the near future, the trophic changes brought about by hunting will have a larger and more rapid impact on Central African rainforest structure and function than the direct impacts of climate change on the vegetation. Immediate hunting regulation is vital for the survival of the Central African rainforest ecosystem.

Social and ecological change over a decade in a village hunting system, central Gabon.

Despite widespread recognition of the major threat to tropical forest biological diversity and local food security posed by unsustainable bushmeat hunting, virtually no long-term studies tracking the socioecological dynamics of hunting systems have been conducted. We interviewed local hunters and collected detailed hunting data to investigate changes in offtake and hunter characteristics over 10 years (2001-2010) in Dibouka and Kouagna villages, central Gabon, in the context of hunter recollections of longer term trends since the 1950s. To control for changes in hunter behavior, such as trap location and characteristics, we report hunting offtake data per trap. Our results suggest the hunting area was already highly depleted by 2001; local hunters reported that 16 large-bodied prey species had become rare or locally extirpated over the last 60 years. Overall, we observed no significant declines in hunting offtake or changes in species composition from 2001 to 2010, and offtakes per trap increased slightly between 2004 and 2010. However, trapping distance from the villages increased, and there was a switch in hunting techniques; a larger proportion of the catch was hunted with guns in 2010. The number of hunters declined by 20% from 2004 to 2010, and male livelihood activities shifted away from hunting. Hunters with the lowest hunting incomes in 2004 were more likely than successful hunters to have moved away from the village by 2010 (often in response to alternative employment opportunities). Therefore, changes in trap success (potentially related to biological factors) were interacting with system-level changes in hunter number and composition (related to external socioeconomic factors) to produce a relatively static overall offtake. Our results highlight the importance of understanding the small-scale context of hunting to correctly interpret changes or apparent stasis in hunting effort and offtake over time.

Distribution and use of income from bushmeat in a rural village, central Gabon.

Bushmeat hunting is an activity integral to rural forest communities that provides a high proportion of household incomes and protein requirements. An improved understanding of the relationship between bushmeat hunting and household wealth is vital to assess the potential effects of future policy interventions to regulate an increasingly unsustainable bushmeat trade. We investigated the relationship between hunting offtake and household wealth, gender differences in spending patterns, and the use of hunting incomes in two rural forest communities, Central Gabon, from 2003 to 2005. Households in which members hunted (hunting households) were significantly wealthier than households in which no one hunted (nonhunting households), but within hunting households offtakes were not correlated with household wealth. This suggests there are access barriers to becoming a hunter and that hunting offtakes may not be the main driver of wealth accumulation. Over half of the money spent by men in the village shop was on alcohol and cigarettes, and the amount and proportion of income spent on these items increased substantially with increases in individual hunting offtake. By contrast, the majority of purchases made by women were of food, but their food purchases decreased actually and proportionally with increased household hunting offtake. This suggests that the availability of bushmeat as a food source decreases spending on food, whereas hunting income may be spent in part on items that do not contribute significantly to household food security. Conservation interventions that aim to reduce the commercial bushmeat trade need to account for likely shifts in individual spending that may ensue and the secondary effects on household economies.

Investigating temporal changes in hybridization and introgression in a predominantly bimodal hybridizing population of invasive sika (Cervus nippon) and native red deer (C. elaphus) on the Kintyre Peninsula, Scotland.

We investigated temporal changes in hybridization and introgression between native red deer (Cervus elaphus) and invasive Japanese sika (Cervus nippon) on the Kintyre Peninsula, Scotland, over 15 years, through analysis of 1513 samples of deer at 20 microsatellite loci and a mtDNA marker. We found no evidence that either the proportion of recent hybrids, or the levels of introgression had changed over the study period. Nevertheless, in one population where the two species have been in contact since approximately 1970, 44% of individuals sampled during the study were hybrids. This suggests that hybridization between these species can proceed fairly rapidly. By analysing the number of alleles that have introgressed from polymorphic red deer into the genetically homogenous sika population, we reconstructed the haplotypes of red deer alleles introduced by backcrossing. Five separate hybridization events could account for all the recently hybridized sika-like individuals found across a large section of the Peninsula. Although we demonstrate that low rates of F1 hybridization can lead to substantial introgression, the progress of hybridization and introgression appears to be unpredictable over the short timescales.

Two distinct STLV-1 subtypes infecting Mandrillus sphinx follow the geographic distribution of their hosts.

The mandrill (Mandrillus sphinx) has been shown to be infected with an STLV-1 closely related to HTLV-1. Two distinct STLV-1 subtypes (D and F) infect wild mandrills with high overall prevalence (27.0%) but are different with respect to their phylogenetic relationship and parallel to the mandrills' geographic range. The clustering of these new STLV-1mnd sequences with HTLV-1 subtype D and F suggests first, past simian-to-human transmissions in Central Africa and second, that species barriers are easier to cross over than geographic barriers.

Molecular evidence for deep phylogenetic divergence in Mandrillus sphinx.

Mandrills (Mandrillus sphinx) are forest primates indigenous to western central Africa. Phylogenetic analysis of 267 base pairs (bp) of the cytochrome b gene from 53 mandrills of known and 17 of unknown provenance revealed two phylogeographical groups, with haplotypes differentiated by 2.6% comprising seven synonymous transitions. The distribution of the haplotypes suggests that the Ogooué River, Gabon, which bisects their range, separates mandrill populations in Cameroon and northern Gabon from those in southern Gabon. The haplotype distribution is also concordant with that of two known mandrill simian immunodeficiency viruses, suggesting that these two mandrill phylogroups have followed different evolutionary trajectories since separation.

Wild Mandrillus sphinx are carriers of two types of lentivirus.

Mandrillus sphinx, a large primate living in Cameroon and Gabon and belonging to the Papionini tribe, was reported to be infected by a simian immunodeficiency virus (SIV) (SIVmndGB1) as early as 1988. Here, we have identified a second, highly divergent SIVmnd (designated SIVmnd-2). Genomic organization differs between the two viral types; SIVmnd-2 has the additional vpx gene, like other SIVs naturally infecting the Papionini tribe (SIVsm and SIVrcm) and in contrast to the other SIVmnd type (here designated SIVmnd-1), which is more closely related to SIVs infecting l'hoest (Cercopithecus lhoesti lhoesti) and sun-tailed (Cercopithecus lhoesti solatus) monkeys. Importantly, our epidemiological studies indicate a high prevalence of both types of SIVmnd; all 10 sexually mature wild-living monkeys and 3 out of 17 wild-born juveniles tested were infected. The geographic distribution of SIVmnd seems to be distinct for the two types: SIVmnd-1 viruses were exclusively identified in mandrills from central and southern Gabon, whereas SIVmnd-2 viruses were identified in monkeys from northern and western Gabon, as well as in Cameroon. SIVmnd-2 full-length sequence analysis, together with analysis of partial sequences from SIVmnd-1 and SIVmnd-2 from wild-born or wild-living mandrills, shows that the gag and pol regions of SIVmnd-2 are closest to those of SIVrcm, isolated from red-capped mangabeys (Cercocebus torquatus), while the env gene is closest to that of SIVmnd-1. pol and env sequence analyses of SIV from a related Papionini species, the drill (Mandrillus leucophaeus), shows a closer relationship of SIVdrl to SIVmnd-2 than to SIVmnd-1. Epidemiological surveys of human immunodeficiency virus revealed a case in Cameroon of a human infected by a virus serologically related to SIVmnd, raising the possibility that mandrills represent a viral reservoir for humans similar to sooty mangabeys in Western Africa and chimpanzees in Central Africa.

Chloroplast DNA variation in a rainforest tree (Aucoumea klaineana, burseraceae) in Gabon.

One of the dominant savannah colonists in Gabon is Aucoumea klaineana or Okoumé (Burseraceae), an endemic species which belongs to a monotypic genus. Chloroplast DNA (cpDNA) variation was studied in this species by means of PCR amplification of 40 kb of cpDNA sequences, followed by restriction analysis of the resulting fragments. No insertion/deletion events were noted, and a single point mutation was found. The level of differentiation among the 19 populations studied was relatively low (GST = 0.54) compared to other plant species (mean of 0.76), in agreement with the pioneer status of the species. However, cpDNA diversity was geographically structured, with the less frequent haplotype occurring only in populations from southern Gabon. This distribution might suggest either that there were two ancient source populations of Okoumé, one in the north and the other in the south, from which the colonizing process of the savannah began after the last ice age, or alternatively that there was one polymorphic source in the south. The low level of cpDNA diversity could indicate that Okoumé populations in these refugia were quite small.

Introgression through rare hybridization: A genetic study of a hybrid zone between red and sika deer (genus Cervus) in Argyll, Scotland.

In this article we describe the structure of a hybrid zone in Argyll, Scotland, between native red deer (Cervus elaphus) and introduced Japanese sika deer (Cervus nippon), on the basis of a genetic analysis using 11 microsatellite markers and mitochondrial DNA. In contrast to the findings of a previous study of the same population, we conclude that the deer fall into two distinct genetic classes, corresponding to either a sika-like or red-like phenotype. Introgression is rare at any one locus, but where the taxa overlap up to 40% of deer carry apparently introgressed alleles. While most putative hybrids are heterozygous at only one locus, there are rare multiple heterozygotes, reflecting significant linkage disequilibrium within both sika- and red-like populations. The rate of backcrossing into the sika population is estimated as H = 0.002 per generation and into red, H = 0.001 per generation. On the basis of historical evidence that red deer entered Kintyre only recently, a diffusion model evaluated by maximum likelihood shows that sika have increased at approximately 9.2% yr-1 from low frequency and disperse at a rate of approximately 3.7 km yr-1. Introgression into the red-like population is greater in the south, while introgression into sika varies little along the transect. For both sika- and red-like populations, the degree of introgression is 30-40% of that predicted from the rates of current hybridization inferred from linkage disequilibria; however, in neither case is this statistically significant evidence for selection against introgression.

The menopause: preparing women for what to expect.

After the age of about 35, the natural cycle becomes less predictable. Oestrogen levels fluctuate, leading to some anovulatory cycles. Sometimes periods stop suddenly but more often become erratic and less frequent for a year or two before the final period (menopause). About 75% of women experience symptoms at the time of the menopause, which typically lasts 1-3 years and occurs at around the age of 50. Long-term effects of the menopause are a rapid decline in bone density and greater risk of heart disease. Useful life-style adjustments for menopausal women are to eat calcium-rich foods, stop smoking, restrict alcohol intake and exercise regularly, especially weight-bearing exercise such as walking, dancing or sports. Hormone replacement therapy (HRT) is effective in reducing menopausal symptoms and appears to reduce the long-term risks of osteoporosis and heart disease. Women may start taking HRT before periods cease if they have troublesome symptoms during the pre- and peri-menopausal stage. Women who have had a hysterectomy may use oestrogen on its own. Women who have a uterus need a combination of oestrogen and progestogen. Current evidence suggests that to take HRT for up to 5-8 years incurs no additional risk of breast cancer, although to take it for longer than 10 years seems to increase the risk slightly.

Population-based study of the adequacy of well-child care services: a rural county's report card.

OBJECTIVE: To determine the adequacy of well-child care services using a population-based study. DESIGN: The medical records of all county providers and the immunization records at the local health department were reviewed. A county birth cohort, identified using electronic birth certificates, was compared with those who migrated into the area (hereafter, in-migrants). SETTING: All primary care sites (private, network, etc) in a rural county. PATIENTS: Two-year-old children born between May 31, 1993, and May 30, 1994. MAIN OUTCOME MEASURES: Immunization rates and preventive screenings. RESULTS: A total of 674 medical records were reviewed. Of these, 377 (56%) belonged to a county birth cohort and 297 (44%) were in-migrants. Medical records of 64% of the birth cohort were reviewed. Among all 2-year-olds, 80% received 4 doses of diphtheria and tetanus toxoids and pertussis vaccine; 89%, 3 doses of Haemophilus influenzae type b (Hib); 75%, 4 doses of Hib; 77%, 3 doses of hepatitis B vaccine; 85%, measles-mumps-rubella vaccine; 85%, 3 doses of oral poliovirus vaccine; 17%, varicella live virus vaccine (Varivax). The 4:3:1 rate was 75% at age 2 years. Sixty-eight percent had had 1 hematocrit, 74% had 1 lead screening test, and 43% had 2 lead screening tests. A total of 64% had had 6 well-child visits and 30% had had 9. The mean number of weights and heights measured was 4.8 and 4.5, respectively, at age 1 year and 7.3 and 6.8, respectively, at age 2 years. The birth cohort had notably higher rates of documented immunization and preventive screening than in-migrants. CONCLUSIONS: This study demonstrated immunization coverage at or below the national average, and well-child care service provisions below American Academy of Pediatrics standards at a county level. This study enabled individual primary care sites to assess their well-child care provision and provided a useful baseline for targeting the improvement of well-child care services in the county.

The establishment of a hybrid zone between red and sika deer (genus Cervus).

Japanese sika deer (Cervus nippon nippon) were introduced to Scotland around 80 years (20 generations) ago. The sika phenotype is expanding its range and hybridizing extensively with native red deer (Cervus elaphus) leading to the establishment of a hybrid zone. This zone is currently moving and cannot be considered to be at equilibrium. Cervid genotypes and mitochondrial haplotypes were mapped across the sika phenotype range, using diagnostic protein isozymes, microsatellite nuclear DNA markers and RFLPs in mtDNA. These were analysed to estimate heterozygote deficits and nuclear linkage disequilibria and cytonuclear disequilibria in relation to gene frequencies and time since contact. Introgression was found in both taxa and strong linkage disequilibria and heterozygote deficits characterize the populations longest exposed to hybridization. Populations further from the introduction site, where hybridization is facilitated by the dispersal of sika-like stages, show low values for linkage disequilibria and heterozygote deficit. The observed patterns in genotype are explained in terms of assortative mating and a selective advantage of the sika genotype. The genetic integrity of the Scottish mainland red deer is shown to be at risk from the invasion of sika.

The human antiporcine cellular repertoire. In vitro studies of acquired and innate cellular responsiveness.

Discordant xenogeneic transplantation offers a potentially unlimited source of donor organs from easily bred, nonendangered, physiologically compatible animals, but has been limited by the inevitable occurrence of hyperacute rejection (HAR). The potential existence of cell-mediated discordant graft rejection has remained obscured by HAR, and hence is incompletely understood. To define the cellular elements capable of recognition of and subsequent response against discordant tissue in a clinically applicable species combination, we have studied the in vitro interaction of human peripheral blood lymphocytes against 3 porcine B lymphoblastoid cell lines and 6 primary porcine endothelial cell populations. PBL from all individuals tested (n = 10) proliferated in response to culture for 72 hr in xenogeneic mixed lymphocyte culture (XMLC) with cell lines expressing porcine MHC (SLA) class II antigens, while endothelial cultures lacking SLA class II generally failed to evoke a response. The proliferative response to class II-positive cells was attenuated by addition of anti-SLA class II antibody but not by anti-SLA class I antibody. Two endothelial populations expressing class II stimulated an inhibitable proliferative response. The magnitude of the short-term proliferative xenogeneic response was similar to that evoked by fully mismatched allogeneic human B lymphoblastoid stimulators. Additionally, extended XMLC was performed with PBL from 3 individuals. All populations responded with continued proliferation when repeatedly stimulated by porcine cells. This was characterized not only by T cell growth, but by prominent NK cell growth as well. Elucidation of the TCR V beta chain usage patterns by semiquantitative PCR documented selection of TCR transcripts from gene family V beta 2 in each group, complemented by a heterogeneous mixture of other transcripts including V beta 17.1, 20.1, and 6.1, suggesting that direct human TCR binding of porcine cells occurs, and that it is likely to be an individualistic response complemented by a more homogeneous NK response. A 51Cr release assay was utilized to demonstrate that unprimed PBL could also lyse porcine target cells. This cytotoxic response was maintained despite the complete removal of T cells, suggesting that porcine-directed NK cell activity is present prior to the maturation of any T cell response. Cytolysis was also demonstrated in serum-free medium and thus was not mediated solely by antibody-dependent cellular cytotoxicity. Chinese hamster ovary cells transfected with the human T cell receptor accessory molecule CD4 were used to study the ability of this molecule to stabilize the interaction between the human TCR and SLA class II.(ABSTRACT TRUNCATED AT 400 WORDS)