Local genetic adaptation to habitat in wild chimpanzees

How populations adapt to their environment is a fundamental question in biology. Yet we know surprisingly little about this process, especially for endangered species such as non-human great apes. Chimpanzees, our closest living relatives, are particularly interesting because they inhabit diverse habitats, from rainforest to woodland-savannah. Whether genetic adaptation facilitates such habitat diversity remains unknown, despite having wide implications for evolutionary biology and conservation. Using 828 newly generated exomes from wild chimpanzees, we find evidence of fine-scale genetic adaptation to habitat. Notably, adaptation to malaria in forest chimpanzees is mediated by the same genes underlying adaptation to malaria in humans. This work demonstrates the power of non-invasive samples to reveal genetic adaptations in endangered populations and highlights the importance of adaptive genetic diversity for chimpanzees.

The application of a new laminitis scoring method to model the rate and pattern of improvement from equine endocrinopathic laminitis in a clinical setting

Background

Endocrinopathic, or hyperinsulinaemia-associated laminitis (HAL) is a common and debilitating equine foot disease, and although no pharmacological treatments are registered, several are under development. To evaluate the effect of such treatments, an accurate and consistent method is needed to track the clinical signs of laminitis over time, and the natural history of the disease, in terms of a ‘normal’ pattern of improvement, needs to be understood. This study examined the improvement pattern in clinical cases of naturally-occurring HAL subjected to a range of best-practice interventions, using two different scoring methods. Eighty horses and ponies with suspected HAL were enrolled in a study conducted at 16 veterinary practices across Germany. The severity of laminitis was assessed by independent veterinarians using both the traditional Obel method and a modified Obel method developed by Meier and colleagues. Assessments were made on the day of diagnosis (d 0), then on days 4, 9, 14, 25 and 42 during the intervention period. Pain medications were withheld for 24 h prior to clinical examination in all cases.

Results

Time to marked improvement from laminitis varied between individuals, but was difficult to monitor accurately using the Obel method, with the median grade being 2/4 on days 0 and 4, then 0/4 from d 9 onwards. More subtle changes could be identified using the Meier method, however, and the median scores were seen to follow the form of an exponential decay model in most horses, improving from 8/12 on d 0, to 0/12 on d 25. Within this composite scoring method, considerable variation was observed in the rate of improvement of individual clinical signs, with the average time taken for each sign to reach a median score of 0 ranging from 4 days (foot lift and weight shifting) to 25 days (gait when turned in a circle) across all 80 horses.

Conclusions

The Meier method provides a reliable and consistent method for monitoring the clinical status of horses with HAL, and despite the variability, the pattern of improvement described here should provide a useful benchmark against which individual cases and new treatments can be assessed.

The efficacy and safety of velagliflozin over 16 weeks as a treatment for insulin dysregulation in ponies

BACKGROUND

A previous six-week (wk) study demonstrated the potential of the sodium-glucose linked transport inhibitor velagliflozin as a novel treatment for equine insulin dysregulation. The present study examined the safety and efficacy of velagliflozin over 16 wk. of treatment, and over 4 wk. of withdrawal. Twenty-four insulin dysregulated ponies were selected, based on their hyper-responsiveness to a diet challenge meal containing 3.8 g non-structural carbohydrates (NSC)/kg bodyweight (BW). Ponies with serum insulin > 90 μIU/mL either 2 or 4 h after feeding were enrolled, and randomly allocated to receive either velagliflozin (0.3 mg/kg BW orally once daily, n = 12), or a placebo (n = 10-12) for 16 wk. The subjects were fed 7.5 g NSC/kg BW/day to maintain a fat body condition. Safety was assessed through daily monitoring, veterinary examination, and the measurement of fasting blood glucose, biochemistry and haematology. Efficacy at reducing post-prandial hyperinsulinemia was assessed using a diet challenge every 8 wk. during treatment and 4 wk. after withdrawal.

RESULTS

Velagliflozin was well accepted by all subjects and caused no adverse effects or hypoglycaemia. Post-prandial serum insulin (insulin Cmax) did not change significantly in the control animals over the entire study period (P = 0.101). In contrast, insulin Cmax (mean ± SE) concentrations fell over time in the velagliflozin-treated group from 205 ± 25 μIU/mL in wk. 0, to 119 ± 19 μIU/mL (P = 0.015) and 117 ± 15 μIU/ml (P = 0.029) after 8 and 16 wk. of treatment, respectively. Although the insulin Cmax in this group was not significantly lower than in controls at wk-8 (P = 0.061), it was lower at wk-16 (P = 0.003), and all 12 treated ponies were below the previously-determined risk threshold for laminitis at this time. After 4 wk. withdrawal, the insulin Cmax returned to 199 ± 36 μIU/mL in the treated group, with no rebound effect.

CONCLUSIONS

Velagliflozin appears to be a promising and safe treatment for equine insulin dysregulation, bringing post-prandial insulin concentrations below the laminitis risk threshold, albeit without normalising them.

Learning curves and teaching when acquiring nut-cracking in humans and chimpanzees

Humans are considered superior to other species in their tool using skills. However, most of our knowledge about animals comes from observations in artificial conditions with individuals removed from their natural environment. We present a first comparison of humans and chimpanzees spontaneously acquiring the same technique as they forage in their natural environment. We compared the acquisition of the Panda nut-cracking technique between Mbendjele foragers from the Republic of Congo and the Taï chimpanzees from Côte d'Ivoire. Both species initially acquire the technique slowly with similar kinds of mistakes, with years of practice required for the apprentice to become expert. Chimpanzees more rapidly acquired the technique when an apprentice, and reached adult efficiency earlier than humans. Adult efficiencies in both species did not differ significantly. Expert-apprentice interactions showed many similar instances of teaching in both species, with more variability in humans due, in part to their more complex technique. While in humans, teaching occurred both vertically and obliquely, only the former existed in chimpanzees. This comparison of the acquisition of a natural technique clarifies how the two species differed in their technical intelligence. Furthermore, our observations support the idea of teaching in both species being more frequent for difficult skills.

Nocturnal activity in wild chimpanzees (Pan troglodytes): Evidence for flexible sleeping patterns and insights into human evolution

OBJECTIVES

We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity.

METHODS

Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity.

RESULTS

We found terrestrial nocturnal activity to occur at 18 of the 22 study sites, at an overall average proportion of 1.80% of total chimpanzee activity, and to occur during all hours of the night, but more frequently during twilight hours. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of forest. We found no effect of the abundance of predators and large mammals, rainfall, or moon illumination.

DISCUSSION

Chimpanzee terrestrial nocturnal activity appears widespread yet infrequent, which suggests a consolidated sleeping pattern. Nocturnal activity may be driven by the stress of high daily temperatures and may be enabled at low levels of human activity. Human activity may exert a relatively greater influence on chimpanzee nocturnal behavior than predator presence. We suggest that chimpanzee nocturnal activity is flexible, enabling them to respond to changing environmental factors.

Poaching empties critical Central African wilderness of forest elephants

Elephant populations are in peril everywhere, but forest elephants in Central Africa have sustained alarming losses in the last decade [1]. Large, remote protected areas are thought to best safeguard forest elephants by supporting large populations buffered from habitat fragmentation, edge effects and human pressures. One such area, the Minkébé National Park (MNP), Gabon, was created chiefly for its reputation of harboring a large elephant population. MNP held the highest densities of elephants in Central Africa at the turn of the century, and was considered a critical sanctuary for forest elephants because of its relatively large size and isolation. We assessed population change in the park and its surroundings between 2004 and 2014. Using two independent modeling approaches, we estimated a 78-81% decline in elephant numbers over ten years - a loss of more than 25,000 elephants. While poaching occurs from within Gabon, cross-border poaching largely drove the precipitous drop in elephant numbers. With nearly 50% of forest elephants in Central Africa thought to reside in Gabon [1], their loss from the park is a considerable setback for the preservation of the species.

Forest elephant movement and habitat use in a tropical forest-grassland mosaic in Gabon

Poaching of forest elephants (Loxodonta cyclotis) for ivory has decimated their populations in Central Africa. Studying elephant movement can provide insight into habitat and resource use to reveal where, when, and why they move and guide conservation efforts. We fitted 17 forest elephants with global positioning system (GPS) collars in 2015 and 2016 in the tropical forest-grassland mosaic of the Wonga Wongué Presidential Reserve (WW), Gabon. Using the location data, we quantified movement distances, home ranges, and habitat use to examine the environmental drivers of elephant movements and predict where elephants occur spatially and temporally. Forest elephants, on average, traveled 2,840 km annually and had home ranges of 713 km², with males covering significantly larger home ranges than females. Forest elephants demonstrated both daily and seasonal movement patterns. Daily, they moved between forest and grassland at dawn and dusk. Seasonally, they spent proportionally more time in grassland than forest during the short-wet season when grasses recruit. Forest elephants also traveled faster during the short-wet season when fruit availability was greatest, likely reflecting long, direct movements to preferred fruiting tree species. Forest elephants tended to select areas with high tree and shrub density that afford cover and browse. When villages occurred in their home ranges elephants spent a disproportionate amount of time near them, particularly in the dry season, probably for access to agricultural crops and preferred habitat. Given the importance of the grassland habitat for elephants, maintenance of the forest-grassland matrix is a conservation priority in WW. Law enforcement, outreach, and education should focus on areas of potential human-elephant conflict near villages along the borders of the reserve. GPS-tracking should be extended into multi-use areas in the peripheries of protected areas to evaluate the effects of human disturbance on elephant movements and to maintain connectivity among elephant populations in Gabon.

Ecological consequences of forest elephant declines for Afrotropical forests

Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant-free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, their loss will have large consequences for the composition and structure of Afrotropical forests. Through a comprehensive literature review, we evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, and tree species composition will depend on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density with release from browsing pressures. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees and thus increase homogeneity of forest structure and decrease carbon stocks. The loss of ecological services by forest elephants likely means Central African forests will be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long-term conservation will require land-use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging.

Technical intelligence and culture: Nut cracking in humans and chimpanzees

OBJECTIVES

According to the technical intelligence hypothesis, humans are superior to all other animal species in understanding and using tools. However, the vast majority of comparative studies between humans and chimpanzees, both proficient tool users, have not controlled for the effects of age, prior knowledge, past experience, rearing conditions, or differences in experimental procedures. We tested whether humans are superior to chimpanzees in selecting better tools, using them more dexteriously, achieving higher performance and gaining access to more resource as predicted under the technical intelligence hypothesis.

MATERIALS AND METHODS

Aka and Mbendjele hunter-gatherers in the rainforest of Central African Republic and the Republic of Congo, respectively, and Taï chimpanzees in the rainforest of Côte d'Ivoire were observed cracking hard Panda oleosa nuts with different tools, as well as the soft Coula edulis and Elaeis guinensis nuts. The nut-cracking techniques, hammer material selection and two efficiency measures were compared.

RESULTS

As predicted, the Aka and the Mbendjele were able to exploit more species of hard nuts in the forest than chimpanzees. However, the chimpanzees were sometimes more efficient than the humans. Social roles differed between the two species, with the Aka and especially the Mbendjele exhibiting cooperation between nut-crackers whereas the chimpanzees were mainly individualistic.

DISCUSSION

Observations of nut-cracking by humans and chimpanzees only partially supported the technical intelligence hypothesis as higher degrees of flexibility in tool selection seen in chimpanzees compensated for use of less efficient tool material than in humans. Nut cracking was a stronger social undertaking in humans than in chimpanzees.

Prospective Randomized Comparison of High-pitch CT at 80 kVp Under Free Breathing with Standard-pitch CT at 100 kVp Under Breath-Hold for Detection of Pulmonary Embolism

RATIONALE AND OBJECTIVES

To prospectively compare high-pitch computed tomography (HPCT) under free breathing (FB) with standard-pitch CT (SPCT) under breath-hold (BH) for detection of pulmonary embolism (PE).

MATERIALS AND METHODS

One hundred consecutive patients (47 females; mean age 58.7 ± 16.6) randomly underwent HPCT-FB (n = 50) or SPCT-BH (n = 50). Radiation doses were documented. One reader measured pulmonary artery attenuation and noise; mean signal-to-noise ratio (SNR) was calculated. Two readers assessed image quality, diagnostic confidence for detection of PE, motion artifacts, assessability of anatomical structures, and presence of transient interruption of contrast as sign of Valsalva maneuver. Inter-reader agreement was calculated.

RESULTS

Radiation dose was significantly lower in HPCT compared to SPCT (2.68 ± 0.60 mGy vs 6.01 ± 2.26 mGy; P < .001). Mean pulmonary artery attenuation and image noise were significantly higher in HPCT (attenuation: 479 Hounsfield unit (HU) vs 343HU; P < .001; noise: 16 HU vs 10 HU; P < .001) whereas SNR was similar between groups (34 HU vs 38 HU; P = .258). HPCT had significantly higher diagnostic confidence for PE detection (P = .048), less cardiac and breathing artifacts (P < .001), better assessability of anatomical structures, and fewer cases of transient interruption of contrast (P < .001) compared to the SPCT.

CONCLUSIONS

HPCT-FB allows for a significant reduction of breathing and motion artifacts compared to SPCT-BH. Diagnostic confidence, assessability of vascular and bronchial structures, as well as SNR are maintained.

An assessment of implications of adaptive licensing for pharmaceutical intellectual property and regulatory exclusivity rights in the European Union

One of the key advantages of adaptive licensing (AL) is to align the licensing of new medicines more closely with patient needs for earlier access to beneficial treatments. From an innovators perspective, "earlier" market access may seem an obvious incentive to gain earlier revenue generation. However, this is offset with an "earlier" start to patent and regulatory protection periods, which, depending on the technology, disease, population, and timing of subsequent asset protection periods, can present a conflict.

Chimpanzee accumulative stone throwing

The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites.

[Endoscopic management of lower gastrointestinal bleeding]

Endoscopic hemostasis is the daily challenge that must be mastered by gastroenterologists. An emergency colonoscopy is the procedure of choice for lower gastrointestinal bleeding because of the diagnostic and therapeutic potential. Colonoscopy should be performed after oral preparation with 4-6 l polyethylene glycol solution within 12 h. In the case of massive hematochezia, colonoscopy without oral preparation employinga mechanical pump is possible and is not associated with a higher rate of complications. Many different endoscopic techniques are available (injection therapy, hemoclips, thermal coagulation, topical hemostatic substances). The suitable and most effective method must be chosen depending on the source of bleeding.

Homelessness and housing crises among individuals accessing services within a Canadian emergency department

ACCESSIBLE SUMMARY

Studies have indicated that individuals who are homeless access hospital emergency departments more frequently and may have different needs than individuals who are housed. Successful interventions have been developed and tested to reduce discharge to homelessness for psychiatric inpatients but have not been similarly tested for discharge from emergency departments. This study was developed to provide baseline data on this issue to inform future emergency department interventions. Findings from the current study suggest that discharge from emergency departments to homelessness happens frequently in London, Canada. Participants are unlikely to spontaneously disclose their housing/homelessness issue when first entering the emergency department, which may result in services that do not adequately meet their complex needs. Screening for housing issues is necessary within emergency departments and psychiatric crisis teams as housing issues may be a reason for accessing care or contribute to the presenting condition. Nurses are in an ideal position to evaluate housing needs among emergency department patients. Services outside of the emergency department are also needed to address housing issues, particularly outside of regular office hours.

ABSTRACT

Individuals who have mental health issues and are homeless or in housing crisis have been found to access emergency departments more frequently than individuals with stable housing. While emergency departments primarily focus on medical issues, homeless individuals may require psychosocial support as well. This study examined issues around housing crises and emergency department use for individuals with mental illness in Canada. Collecting baseline data about these issues is important to inform subsequent interventions. Administrative data from a hospital emergency department and psychiatric crisis service were collected, and five individuals accessing the emergency department for psychiatric reasons were interviewed. Results indicated that individuals with an identified housing crisis accessed the emergency department 930 times in 6 months. None of the interview participants identified housing as the primary reason for accessing the emergency department, but all noted that housing was a contributing stressor. Future research is needed to examine ways in which discharge to homelessness from emergency departments can be avoided and identify alternative services to address housing concerns, particularly for individuals with mental illness. Crisis service and emergency department staff, especially nurses, can play an important role in screening for housing issues and connecting individuals to outside services.