How deregulation, drought and increasing fire impact Amazonian biodiversity.

Biodiversity contributes to the ecological and climatic stability of the Amazon Basin1,2, but is increasingly threatened by deforestation and fire3,4. Here we quantify these impacts over the past two decades using remote-sensing estimates of fire and deforestation and comprehensive range estimates of 11,514 plant species and 3,079 vertebrate species in the Amazon. Deforestation has led to large amounts of habitat loss, and fires further exacerbate this already substantial impact on Amazonian biodiversity. Since 2001, 103,079-189,755 km2 of Amazon rainforest has been impacted by fires, potentially impacting the ranges of 77.3-85.2% of species that are listed as threatened in this region5. The impacts of fire on the ranges of species in Amazonia could be as high as 64%, and greater impacts are typically associated with species that have restricted ranges. We find close associations between forest policy, fire-impacted forest area and their potential impacts on biodiversity. In Brazil, forest policies that were initiated in the mid-2000s corresponded to reduced rates of burning. However, relaxed enforcement of these policies in 2019 has seemingly begun to reverse this trend: approximately 4,253-10,343 km2 of forest has been impacted by fire, leading to some of the most severe potential impacts on biodiversity since 2009. These results highlight the critical role of policy enforcement in the preservation of biodiversity in the Amazon.

Human-induced ecological cascades: Extinction, restoration, and rewilding in the Galápagos highlands.

Oceanic islands support unique biotas but often lack ecological redundancy, so that the removal of a species can have a large effect on the ecosystem. The larger islands of the Galápagos Archipelago once had one or two species of giant tortoise that were the dominant herbivore. Using paleoecological techniques, we investigate the ecological cascade on highland ecosystems that resulted from whalers removing many thousands of tortoises from the lowlands. We hypothesize that the seasonal migration of a now-extinct tortoise species to the highlands was curtailed by decreased intraspecific competition. We find the trajectory of plant community dynamics changed within a decade of the first whaling vessels visiting the islands. Novel communities established, with a previously uncommon shrub, Miconia, replacing other shrubs of the genera Alternanthera and Acalypha. It was, however, the introduction of cattle and horses that caused the local extirpation of plant species, with the most extreme impacts being evident after c. 1930. This modified ecology is considered the natural state of the islands and has shaped subsequent conservation policy and practice. Restoration of El Junco Crater should emphasize exclusion of livestock, rewilding with tortoises, and expanding the ongoing plantings of Miconia to also include Acalypha and Alternanthera.

Warming, drought, and disturbances lead to shifts in functional composition: A millennial-scale analysis for Amazonian and Andean sites.

Tropical forests are changing in composition and productivity, probably in response to changes in climate and disturbances. The responses to these multiple environmental drivers, and the mechanisms underlying the changes, remain largely unknown. Here, we use a functional trait approach on timescales of 10,000 years to assess how climate and disturbances influence the community-mean adult height, leaf area, seed mass, and wood density for eight lowland and highland forest landscapes. To do so, we combine data of eight fossil pollen records with functional traits and proxies for climate (temperature, precipitation, and El Niño frequency) and disturbances (fire and general disturbances). We found that temperature and disturbances were the most important drivers of changes in functional composition. Increased water availability (high precipitation and low El Niño frequency) generally led to more acquisitive trait composition (large leaves and soft wood). In lowland forests, warmer climates decreased community-mean height probably because of increased water stress, whereas in highland forests warmer climates increased height probably because of upslope migration of taller species. Disturbance increased the abundance of acquisitive, disturbance-adapted taxa with small seeds for quick colonization of disturbed sites, large leaves for light capture, and soft wood to attain fast height growth. Fire had weak effects on lowland forests but led to more stress-adapted taxa that are tall with fast life cycles and small seeds that can quickly colonize burned sites. Site-specific analyses were largely in line with cross-site analyses, except for varying site-level effects of El Niño frequency and fire activity, possibly because regional patterns in El Niño are not a good predictor of local changes, and charcoal abundances do not reflect fire intensity or severity. With future global changes, tropical Amazonian and Andean forests may transition toward shorter, drought- and disturbance-adapted forests in the lowlands but taller forests in the highlands.

On the vital role of enamel prism interfaces and graded properties in human tooth survival.

Teeth of omnivores face a formidable evolutionary challenge: how to protect against fracture and abrasive wear caused by the wide variety of foods they process. It is hypothesized that this challenge is met in part by adaptations in enamel microstructure. The low-crowned teeth of humans and some other omnivorous mammals exhibit multiple fissures running longitudinally along the outer enamel walls, yet remain intact. It is proposed that inter-prism weakness and enamel property gradation act together to avert entry of these fissures into vulnerable inner tooth regions and, at the same time, confer wear resistance at the occlusal surface. A simple indentation experiment is employed to quantify crack paths and energetics in human enamel, and an extended-finite-element model to evaluate longitudinal crack growth histories. Consideration is given as to how tooth microstructure may have played a vital role in human evolution, and by extension to other omnivorous mammals.

A 7000-year history of changing plant trait composition in an Amazonian landscape; the role of humans and climate.

Tropical forests are shifting in species and trait composition, but the main underlying causes remain unclear because of the short temporal scales of most studies. Here, we develop a novel approach by linking functional trait data with 7000 years of forest dynamics from a fossil pollen record of Lake Sauce in the Peruvian Amazon. We evaluate how climate and human disturbances affect community trait composition. We found weak relationships between environmental conditions and traits at the taxon level, but strong effects for community-mean traits. Overall, community-mean traits were more responsive to human disturbances than to climate change; human-induced erosion increased the dominance of dense-wooded, non-zoochorous species with compound leaves, and human-induced fire increased the dominance of tall, zoochorous taxa with large seeds and simple leaves. This information can help to enhance our understanding of forest responses to past environmental changes, and improve predictions of future changes in tropical forest composition.

A definition of free sugars for the UK.

Public Health England has set a definition for free sugars in the UK in order to estimate intakes of free sugars in the National Diet and Nutrition Survey. This follows the recommendation from the Scientific Advisory Committee on Nutrition in its 2015 report on Carbohydrates and Health that a definition of free sugars should be adopted. The definition of free sugars includes: all added sugars in any form; all sugars naturally present in fruit and vegetable juices, purées and pastes and similar products in which the structure has been broken down; all sugars in drinks (except for dairy-based drinks); and lactose and galactose added as ingredients. The sugars naturally present in milk and dairy products, fresh and most types of processed fruit and vegetables and in cereal grains, nuts and seeds are excluded from the definition.

Exercise is medicine: student pharmacists' perceptions and knowledge of exercise prescription.

With healthcare costs on the rise, a global initiative was launched in 2007, called Exercise is Medicine, to prescribe and counsel patients on exercise to aid in the prevention and treatment of chronic diseases. Since community pharmacists are one of the most accessible healthcare providers, this is an opportunity for pharmacists to also engage in this initiative. This study aimed to assess pharmacy student perceptions and knowledge on exercise to determine whether they are adequately prepared to counsel patients on exercise prescription. Third and fourth year pharmacy students were surveyed to test their basic knowledge of exercise prescription. Results show that 93.5% of students agreed or strongly agreed that it is important for pharmacists to counsel patients about exercise. The mean (SD) score for the 11 basic knowledge quiz questions on exercise prescription was 28.9% (SD 16.8), with no significant difference between third and fourth year pharmacy students. While students deemed exercise counseling as important, students proved deficient in exercise prescription knowledge. Schools of pharmacy may consider increasing curricular content to be congruent with this initiative.

Human disturbance amplifies Amazonian El Niño-Southern Oscillation signal.

The long-term interaction between human activity and climate is subject to increasing scrutiny. Humans homogenize landscapes through deforestation, agriculture, and burning and thereby might reduce the capacity of landscapes to provide archives of climate change. Alternatively, land-use change might overwhelm natural buffering and amplify latent climate signals, rendering them detectable. Here we examine a sub-annually resolved sedimentary record from Lake Sauce in the western Amazonian lowlands that spans 6900 years. Finely-laminated sediments were deposited from ca. 5000 years ago until the present, and human activity in the watershed was revealed through the presence of charcoal and maize agriculture. The laminations, analyzed for color content and bandwidth, showed distinctive changes that were coupled to more frequent occurrence of fossil maize pollen. As agricultural activity intensified ca. 2200 cal. BP, the 2- to 8-year periodicity characteristic of El Niño-Southern Oscillation became evident in the record. These agricultural activities appeared to have amplified an existing, but subtle climatic signal that was previously absorbed by natural vegetation. When agricultural activity slowed, or land use around Lake Sauce changed at ca. 800 cal. BP, the signal of El Niño-Southern Oscillation (ENSO) activity became erratic.

Andean microrefugia: testing the Holocene to predict the Anthropocene.

Microrefugia are important for supporting populations during periods of unfavourable climate change and in facilitating rapid migration as conditions ameliorate. With ongoing anthropogenic climate change, microrefugia could have an important conservation value; however, a simple tool has not been developed and tested to predict which settings are microrefugial. We provide a tool based on terrain ruggedness modelling of individual catchments to predict Andean microrefugia. We tested the predictions using nine Holocene Polylepis pollen records. We used the mid-Holocene dry event, a period of peak aridity for the last 100 000 yr, as an analogue climate scenario for the near future. The results suggest that sites with high terrain rugosity have the greatest chance of sustaining mesic conditions under drier-than-modern climates. Fire is a feature of all catchments; however, an increase in fire is only recorded in settings with low rugosity. Owing to rising temperatures and greater precipitation variability, Andean ecosystems are threatened by increasing moisture stress. Our results suggest that high terrain rugosity helps to create more resilient catchments by trapping moisture through orographic rainfall and providing firebreaks that shelter forest from fire. On this basis, conservation policy should target protection and management of catchments with high terrain rugosity.

The functional extinction of Andean megafauna.

Controversy exists over the cause and timing of the extinction of the Pleistocene megafauna. In the tropical Andes, deglaciation and associated rapid climate change began ~8,000 years before human arrival, providing an opportunity to separate the effects of climate change from human hunting on megafaunal extinction. We present a paleoecological record spanning the last 25,000 years from Lake Pacucha, Peru (3,100 m elevation). Fossil pollen, charcoal, diatoms, and the dung fungus Sporormiella, chronicle a two-stage megaherbivore population collapse. Sporormiella abundance, the proxy for megafaunal presence, fell sharply at ~21,000 years ago, but rebounded prior to a permanent decline between ~16,800 and 15,800 years ago. This two-stage decline in megaherbivores resulted in a functional extinction by ~15,800 years ago, 3,000 years earlier than known human occupation of the high Andes. Declining megaherbivore populations coincided with warm, wet intervals. Climatic instability and megafaunal population collapse triggered an ecological cascade that resulted in novel floral assemblages, and increases in woody species, fire frequency, and plant species that were sensitive to trampling. Our data revealed that Andean megafaunal populations collapsed due to positive feedbacks between habitat quality and climate change rather than human activity.

A finite element model validates an external mechanism for opening the urethral tube prior to micturition in the female.

PURPOSE: Existing theories for micturition in the female mandate total relaxation of the pelvic floor while detrusor pressure pushes the urethra open. However, video X-ray and electromyogram data indicate that micturition is preceded by active outwards opening of the outflow tract by backward-/downward-acting muscle vectors. If the detrusor pressure alone is enough to expand the tube, why does the active opening take place? The aim was to model the urethral tube in detail to assess the relative importance of the active opening mechanism and detrusor pressure. METHODS: Finite element methods were used to model the urethral tube in detail. Nonlinear-elastic properties similar to urethral component tissues were taken from the literature. The boundary conditions applied to the tube model included internal pressure due to detrusor contraction (60 cm H2O) and various displacements and constraints such as pubourethral and pubovesical ligament attachments. RESULTS: In order to achieve opening dimensions similar to those in the lateral X-ray under the action of detrusor pressure alone, the pressure had to be increased by two orders of magnitude above normal levels. CONCLUSIONS: Normal detrusor pressure alone is not sufficient to achieve opening of the urethra against the elasticity of the constituent tissues, suggesting that normal micturition requires an active mechanism provided by backward-/downward-acting pelvic floor muscles, as predicted by the integral theory.

Patients' administration preferences: progesterone vaginal insert (Endometrin®) compared to intramuscular progesterone for Luteal phase support.

BACKGROUND: Administration of exogenous progesterone for luteal phase support has become a standard of practice. Intramuscular (IM) injections of progesterone in oil (PIO) and vaginal administration of progesterone are the primary routes of administration. This report describes the administration preferences expressed by women with infertility that were given progesterone vaginal insert (PVI) or progesterone in oil injections (PIO) for luteal phase support during fresh IVF cycles. METHODS: A questionnaire to assess the tolerability, convenience, and ease of administration of PVI and PIO given for luteal phase support was completed by infertile women diagnosed with PCOS and planning to undergo IVF. The women participated in an open-label study of highly purified human menopausal gonadotropins (HP-hMG) compared with recombinant FSH (rFSH) given for stimulation of ovulation. RESULTS: Most women commented on the convenience and ease of administration of PVI, while a majority of women who administered IM PIO described experiencing pain. In addition, their partners often indicated that they had experienced at least some anxiety regarding the administration of PIO. The most distinguishing difference between PVI and PIO in this study was the overall patient preference for PVI. Despite the need to administer PVI either twice a day or three times a day, 82.6% of the patients in the PVI group found it "very" or "somewhat convenient" compared with 44.9% of women in the PIO group. CONCLUSIONS: The results of this comprehensive, prospective patient survey, along with findings from other similar reports, suggest that PVI provides an easy-to-use and convenient method for providing the necessary luteal phase support for IVF cycles without the pain and inconvenience of daily IM PIO. Moreover, ongoing pregnancy rates with the well-tolerated PVI were as good as the pregnancy rates with PIO. TRIAL REGISTRATION: ClinicalTrial.gov, NCT00805935.

Underactive bladder, Fowler's syndrome are potentially curable by uterosacral ligament repair.

Underactive bladder (UAB) is essentially an inability of the bladder to properly empty. UAB symptoms, when they co-occur with posterior fornix syndrome (PFS) symptoms (urge, frequency, nocturia, chronic pelvic pain), can be cured/improved, surgically by uterosacral ligament (USL) repair, non-surgically, by devices which give mechanical support of the USLs or strengthening pelvic muscle and ligaments with squatting-based exercises. The pathogenic pathway from weak USLs to UAB (and PFS) is that, when the muscles which externally open the posterior wall of the urethra contract against lax USLs, their contractile force weakens, and they cannot open the urethra adequately. The detrusor then contracts against a relatively unopened urethra to cause obstructive symptoms (i.e., UAB) such as slow stream, intermittent stream (stopping and starting), hesitancy (difficulty starting), feeling of incomplete emptying, and post-micturition dribble. Co-occurrence of PFS symptoms indicates that UAB may be part of the PFS, with USL causation, which can be tested by a tampon or probe in the posterior fornix. If the emptying (and other) PFS symptoms improve, it is a sign that UAB, and Fowler's syndrome (FS) can potentially be cured or improved by USL repair. Following USL repair, many studies have recorded very significant improvement in emptying symptoms, and objective tests, for example, postvoid residual (PVR), decreased natural bladder volume, and decreased emptying time. FS and UAB are most likely a part of the PFS and, therefore, potentially curable by USL repair.

A brief physiology and pathophysiology of the bladder.

The remit of this review is confined to experimental works and publications relevant to the integral theory of female urinary incontinence (IT). Since its first publication in 1990, the IT has challenged the general view that the pathogenesis of overactive bladder (OAB) (urge, frequency, nocturia) is unknown and there is no cure. According to the IT, normal function bladder control is binary, either closed or open. Control is cortical via a peripheral feedback component: oppositely acting reflex striated pelvic muscles contract against suspensory ligaments to close the urethra for continence, open it prior to evacuation, and stretch the vagina like a trampoline to prevent excess impulses from the urothelial stretch receptors which may cause unwanted urgency at low bladder volumes (OAB). The pathogenesis of female urinary incontinence is from outside the bladder, mainly weak ligaments or vagina, due to collagen deficiency. Damage in childbirth (collagen depolymerization) and age (collagen loss) make ligaments vulnerable to damage. With weak ligaments, muscles contracting against them weaken: the muscles cannot close the urethra (manifested as stress incontinence), open it (manifested as emptying problems or retention) or stretch the vagina to prevent the urothelial stretch receptors firing off prematurely (manifested as urge incontinence). Weak pubourethral ligaments can cause stress urinary incontinence (SUI), or SUI plus urge (mixed incontinence). Weak uterosacral ligaments (USLs) can cause urge, frequency, nocturia and emptying difficulties. Treatment consisting of surgical/non-surgical strengthening of ligaments can cure or improve SUI, OAB, and emptying dysfunctions. In summary, bladder control is from outside the bladder, binary, with cortical and peripheral components. A small change in definition, from "overactive" to "overactivated" is consistent with this concept, retains the acronym "OAB", and opens the door to probability of cure and a massive increase in research endeavours.

Phytolith assemblages reflect variability in human land use and the modern environment.

Phytoliths preserved in soils and sediments can be used to provide unique insights into past vegetation dynamics in response to human and climate change. Phytoliths can reconstruct local vegetation in terrestrial soils where pollen grains typically decay, providing a range of markers (or lack thereof) that document past human activities. The ca. 6 million km2 of Amazonian forests have relatively few baseline datasets documenting changes in phytolith representation across gradients of human disturbances. Here we show that phytolith assemblages vary on local scales across a gradient of (modern) human disturbance in tropical rainforests of Suriname. Detrended correspondence analysis showed that the phytolith assemblages found in managed landscapes (shifting cultivation and a garden), unmanaged forests, and abandoned reforesting sites were clearly distinguishable from intact forests and from each other. Our results highlight the sensitivity and potential of phytoliths to be used in reconstructing successional trajectories after site usage and abandonment. Percentages of specific phytolith morphotypes were also positively correlated with local palm abundances derived from UAV data, and with biomass estimated from MODIS satellite imagery. This baseline dataset provides an index of likely changes that can be observed at other sites that indicate past human activities and long-term forest recovery in Amazonia. Supplementary Information: The online version contains supplementary material available at 10.1007/s00334-023-00932-2.

Population Pharmacokinetic Modeling of Abacavir/Dolutegravir/Lamivudine to Support a Fixed-Dose Combination in Children with HIV-1.

INTRODUCTION: Once-daily fixed-dose combinations (FDC) containing abacavir (ABC), dolutegravir (DTG), and lamivudine (3TC) have been approved in the US for adults and children with HIV weighing ≥ 6 kg. This analysis assessed the ability of previously developed ABC, DTG, and 3TC pediatric population pharmacokinetic (PopPK) models using multiple formulations to describe and predict PK data in young children using dispersible tablet (DT) and tablet formulations of ABC/DTG/3TC FDC in the IMPAACT 2019 study. METHODS: IMPAACT 2019 was a Phase I/II study assessing the PK, safety, tolerability, and efficacy of ABC/DTG/3TC FDC in children with HIV-1. Intensive and sparse PK samples were collected over 48 weeks. Existing drug-specific pediatric PopPK models for ABC (2-compartment), DTG (1-compartment), and 3TC (1-compartment) were applied to the IMPAACT 2019 drug concentration data without re-estimation (external validation) of PopPK parameters. Drug exposures were then simulated across World Health Organization weight bands for children weighing ≥ 6 to < 40 kg for each drug and compared with pre-defined exposure target ranges. RESULTS: Goodness-of-fit and visual predictive check plots demonstrated that the previously developed pediatric PopPK models sufficiently described and predicted the data. Thus, new PopPK models describing the IMPAACT 2019 data were unnecessary. Across weight bands, the predicted geometric mean (GM) for ABC AUC0-24 ranged from 14.89 to 18.50 µg*h/ml, DTG C24 ranged from 0.74 to 0.95 µg/ml, and 3TC AUC0-24 ranged from 10.50 to 13.20 µg*h/ml. These exposures were well within the pre-defined target ranges set for each drug. CONCLUSION: This model-based approach leveraged existing pediatric data and models to confirm dosing of ABC/DTG/3TC FDC formulations in children with HIV-1. This analysis supports ABC/DTG/3TC FDC dosing in children weighing ≥ 6 kg.

Development of a physiologically based pharmacokinetic model of fostemsavir and its pivotal application to support dosing in pregnancy.

It is critical to understand the impact of significant physiological changes during pregnancy on the extent of maternal and fetal drug exposure. Fostemsavir (FTR) is a prodrug of temsavir (TMR) and is approved in combination with other antiretrovirals for multi-drug-resistant human immunodeficiency virus (HIV) infections. This physiologically based pharmacokinetic model (PBPK) study was used to estimate TMR PK in pregnant populations during each trimester of pregnancy to inform FTR dosing. A PBPK model was developed and validated for TMR using PK data collected following intravenous TMR and oral FTR dosing (immediate-release and extended-release tablets) in healthy volunteers. Predicted TMR concentration-time profiles accurately predicted the reported clinical data and variability in healthy (dense data) and pregnant (sparse data) populations. Predicted versus observed TMR geometric mean (CV%) clearance following intravenous administration was 18.01 (29) versus 17 (21) (L/h). Predicted versus observed TMR AUC0-inf (ng.h/mL) in healthy volunteers following FTR administration of the extended-release tablet were 9542 (66) versus 7339 (33). The validated TMR PBPK model was then applied to predict TMR PK in a population of pregnant individuals during each trimester. Simulations showed TMR AUC in pregnant individuals receiving FTR 600 mg twice daily was decreased by 25% and 38% in the second and third trimesters, respectively. However, TMR exposure remained within the range observed in nonpregnant adults with no need for dose adjustment. The current PBPK model can also be applied for the prediction of local tissue concentrations and drug-drug interactions in pregnancy.

The Evolution of Agrarian Landscapes in the Tropical Andes.

Changes in land-use practices have been a central element of human adaptation to Holocene climate change. Many practices that result in the short-term stabilization of socio-natural systems, however, have longer-term, unanticipated consequences that present cascading challenges for human subsistence strategies and opportunities for subsequent adaptations. Investigating complex sequences of interaction between climate change and human land-use in the past-rather than short-term causes and effects-is therefore essential for understanding processes of adaptation and change, but this approach has been stymied by a lack of suitably-scaled paleoecological data. Through a high-resolution paleoecological analysis, we provide a 7000-year history of changing climate and land management around Lake Acopia in the Andes of southern Peru. We identify evidence of the onset of pastoralism, maize cultivation, and possibly cultivation of quinoa and potatoes to form a complex agrarian landscape by c. 4300 years ago. Cumulative interactive climate-cultivation effects resulting in erosion ended abruptly c. 2300 years ago. After this time, reduced sedimentation rates are attributed to the construction and use of agricultural terraces within the catchment of the lake. These results provide new insights into the role of humans in the manufacture of Andean landscapes and the incremental, adaptive processes through which land-use practices take shape.