Future malaria environmental suitability in Africa is sensitive to hydrology.

Changes in climate shift the geographic locations that are suitable for malaria transmission because of the thermal constraints on vector Anopheles mosquitos and Plasmodium spp. malaria parasites and the lack of availability of surface water for vector breeding. Previous Africa-wide assessments have tended to solely represent surface water using precipitation, ignoring many important hydrological processes. Here, we applied a validated and weighted ensemble of global hydrological and climate models to estimate present and future areas of hydroclimatic suitability for malaria transmission. With explicit surface water representation, we predict a net decrease in areas suitable for malaria transmission from 2025 onward, greater sensitivity to future greenhouse gas emissions, and different, more complex, malaria transmission patterns. Areas of malaria transmission that are projected to change are smaller than those estimated by precipitation-based estimates but are associated with greater changes in transmission season lengths.

Targeted policy intervention for reducing red meat consumption: conflicts and trade-offs.

BACKGROUND: There are a range of policies and guidelines focused on meat consumption which aim to tackle health and environmental issues. Policies are often siloed in nature and propose universal limits on consumption. Despite this, there will be a number of conflicts and trade-offs between interest groups. This study explores secondary impacts associated with guidelines issued by the World Cancer Research Fund and assesses the utility of a targeted policy intervention strategy for reducing red meat consumption. METHODS: We used highly detailed consumption data of over 5,000 individuals from the National Diet and Nutrition Survey. We firstly compared individual consumption against the policy guidelines to identify demographic groups most likely to consume above recommended levels. We then synthetically modified the food diary data to investigate the secondary impacts of adherence to the recommendations by all individuals. We assessed changes in overall consumption, nutrient intake (iron, zinc, vitamin B12, vitamin B3, fat and saturated fat) and global warming potential. We also projected future impacts under various population projections. RESULTS: We found that certain demographic groups are much more likely to exceed the recommendations and would therefore benefit from a targeted intervention approach. Our results provide a baseline for which the impacts of any meat substitute diets can be assessed against. Whilst secondary health benefits may be realised by reducing intake of certain nutrients (e.g. fats), negative impacts may occur due to the reduced intake of other nutrients (e.g. iron, zinc). Reduced overall consumption is likely to have implications for the wider meat industry whilst complementary impacts would occur in terms of reduced greenhouse gas emissions. Impacts will be counteracted or maybe even reversed by any substitute products, highlighting the need to carefully consider the suitability and impacts of meat-replacements. CONCLUSION: The future structure of the meat industry will depend on how conflicts and trade-offs are addressed and how more holistic policy ideas are implemented. This research provides a framework for using demographic and consumption data to reduce negative trade-offs and improve policy effectiveness.

Accelerated mass loss of Himalayan glaciers since the Little Ice Age.

Himalayan glaciers are undergoing rapid mass loss but rates of contemporary change lack long-term (centennial-scale) context. Here, we reconstruct the extent and surfaces of 14,798 Himalayan glaciers during the Little Ice Age (LIA), 400 to 700 years ago. We show that they have lost at least 40 % of their LIA area and between 390 and 586 km3 of ice; 0.92 to 1.38 mm Sea Level Equivalent. The long-term rate of ice mass loss since the LIA has been between - 0.011 and - 0.020 m w.e./year, which is an order of magnitude lower than contemporary rates reported in the literature. Rates of mass loss depend on monsoon influence and orographic effects, with the fastest losses measured in East Nepal and in Bhutan north of the main divide. Locally, rates of loss were enhanced with the presence of surface debris cover (by 2 times vs clean-ice) and/or a proglacial lake (by 2.5 times vs land-terminating). The ten-fold acceleration in ice loss we have observed across the Himalaya far exceeds any centennial-scale rates of change that have been recorded elsewhere in the world.

Geodemographic Patterns of Meat Expenditure in Great Britain.

The future of the meat industry will require the management of important trade-offs between economic, environmental and health aspects of both humans and animals. Understanding the patterns and trends of meat expenditure and consumption is crucial for assessing the current resilience of the system and for economic, planning, health and environmental applications. Here, we show how the technique of geodemographic classification, combined with fine scale expenditure estimates can be used to explore temporal and spatial patterns of meat expenditure in Great Britain between 2008 and 2017. Whilst the expenditure patterns of some food categories such as sausages remained relatively consistent, others such as lamb show a trend towards a reduced proportion of expenditure and increased inequality of purchases. Short term changes in expenditure patterns also occurred, potentially due to product specific price variability, price elasticities or zoonotic disease scare. Environmental attitudes, financial constraints and the prominence of communities who do not eat meat for religious or cultural reasons are likely to be driving the differences between geodemographic groups. The methodology and results could be a valuable tool for policy makers in the meat industry and beyond.

Geographical distribution of fertility rates in 70 low-income, lower-middle-income, and upper-middle-income countries, 2010-16: a subnational analysis of cross-sectional surveys.

BACKGROUND: Understanding subnational variation in age-specific fertility rates (ASFRs) and total fertility rates (TFRs), and geographical clustering of high fertility and its determinants in low-income and middle-income countries, is increasingly needed for geographical targeting and prioritising of policy. We aimed to identify variation in fertility rates, to describe patterns of key selected fertility determinants in areas of high fertility. METHODS: We did a subnational analysis of ASFRs and TFRs from the most recent publicly available and nationally representative cross-sectional Demographic and Health Surveys and Multiple Indicator Cluster Surveys collected between 2010 and 2016 for 70 low-income, lower-middle-income, and upper-middle-income countries, across 932 administrative units. We assessed the degree of global spatial autocorrelation by using Moran's I statistic and did a spatial cluster analysis using the Getis-Ord Gi* local statistic to examine the geographical clustering of fertility and key selected fertility determinants. Descriptive analysis was used to investigate the distribution of ASFRs and of selected determinants in each cluster. FINDINGS: TFR varied from below replacement (2·1 children per women) in 36 of the 932 subnational regions (mainly located in India, Myanmar, Colombia, and Armenia), to rates of 8 and higher in 14 subnational regions, located in sub-Saharan Africa and Afghanistan. Areas with high-fertility clusters were mostly associated with areas of low prevalence of women with secondary or higher education, low use of contraception, and high unmet needs for family planning, although exceptions existed. INTERPRETATION: Substantial within-country variation in the distribution of fertility rates highlights the need for tailored programmes and strategies in high-fertility cluster areas to increase the use of contraception and access to secondary education, and to reduce unmet need for family planning. FUNDING: Wellcome Trust, the UK Foreign, Commonwealth and Development Office, and the Bill & Melinda Gates Foundation.

Ice thickness and volume changes across the Southern Alps, New Zealand, from the little ice age to present.

Rapid changes observed today in mountain glaciers need to be put into a longer-term context to understand global sea-level contributions, regional climate-glacier systems and local landscape evolution. In this study we determined volume changes for 400 mountain glaciers across the Southern Alps, New Zealand for three time periods; pre-industrial "Little Ice Age (LIA)" to 1978, 1978 to 2009 and 2009 to 2019. At least 60 km3 ± 12 km3 or between 41 and 62% of the LIA total ice volume has been lost. The rate of mass loss has nearly doubled from - 0.4 m w.e year-1 during 1,600 to 1978 to - 0.7 m w.e year-1 at present. In comparison Patagonia has lost just 11% of it's LIA volume. Glacier ice in the Southern Alps has become restricted to higher elevations and to large debris-covered ablation tongues terminating in lakes. The accelerating rate of ice loss reflects regional-specific climate conditions and suggests that peak glacial meltwater production is imminent if not already passed, which has profound implications for water resources and riverine habitats.

Is exposure to high levels of maternal intrauterine testosterone a causal factor common to male sex, autism, gender dysphoria, and non-right-handedness?

We present evidence that male sex, autism, gender dysphoria and non-right-handedness share a common cause, viz. high levels of maternal first-trimester intrauterine testosterone. This provides an explanation for the (as yet unexplained) co-occurrences and co-morbidities between these conditions and pathologies.

The human sex ratio at conception.

A recent study has attempted to estimate the primary sex ratio i.e. the sex ratio at conception, using a variety of studies in the extant literature. Starting with data at birth, the authors projected back in time, estimating foetal loss at each gestational stage. Their overall conclusion was that there are equal numbers of males and females formed at conception. This paper contradicts these estimates using two very large samples of accurately recorded 19th century births. These datasets come from a time when contraception and sex selection were not widely practised. The conclusions are that at the time of conception, there is a substantial excess of males, the excess probably being determined by the hormone levels of both parents in accord with the hormonal hypothesis, and if conditions during pregnancy are stressful, then frail male foetuses will preferentially be culled. In short, more males than females are conceived, and that more males are miscarried, and that more males still survive to birth.

The significance of the low sex ratios of offspring and of sibs of probands with systemic lupus erythematosus or rheumatoid arthritis.

There is good evidence that there are significantly low sex ratios (proportions male) in the offspring of patients with some immune diseases e.g. systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). There is also strong evidence that there are significantly low sex ratios in the sibs of patients with SLE and RA and it has been suggested that the low SLE sib sex ratio may be explained by male fetal loss. However, no explanations for these low sex ratios has been established. Bearing in mind the posited hormonal involvement in immune processes, this paper suggesst an additional potential solution. It is that both the pathology and the sex ratio share a hormonal cause - testosterone. The argument depends on the hormonal hypothesis of sex ratio. This paper will describe the hypothesis and describe its relevance to SLE and RA.

Potential explanations of behavioural and other differences and similarities between males and females with autism spectrum disorder.

Several potential explanations may be dependent on the dynamics of prenatal and postnatal testosterone in males and females, and to be consistent with Baron-Cohen's concept of extreme male brain. This paper explores the evidence that male and female autistic subjects differ on the average in that they have had different exposures to the causes of autism, females bearing higher genetic burdens for ASD (autistic spectrum disorder), and males having a greater exposure to high intrauterine levels of testosterone (T). The high levels of intrauterine (and possibly postnatal) testosterone to which ASD cases have been exposed, cause a less masculinized physical habitus (including facial features) in exposed males, and a more masculinized physical habitus in exposed females. ASD genes (as opposed to intrauterine testosterone) are mainly responsible for a low mean IQ in ASD (especially female cases). Exposure to high intrauterine T increases the probability that foetuses will be male, thus potentially explaining the high sex ratio (proportion male) of cases of ASD. The Gender Incoherence Model seems to be based on facts unrelated directly to autism. The shifts towards the other sex are argued to be consequent on sex-different reactions to prenatal exposure to high T, not on the pathology itself. The suspected underdiagnosis of female cases is partially dependent on the different proportions of environmental and genetic causes to which male and female cases are hypothesized to have been exposed, and the consequent 'more normal' behaviour of female cases.

Local level estimates of food, drink and tobacco expenditure for Great Britain.

We present expenditure estimates for 106 product categories across Great Britain for the years 2008-2016. Estimates are at the Local Authority District level (n = 380) and the categories cover all food, drink and tobacco commodities. Reliable, local level expenditure estimates are crucial for understanding broader market trends, assessing economic stability and for projections. This is especially important for commodities such as alcohol, tobacco and unhealthy foods due to their role in the prevalence of non-communicable diseases. There has been relatively little research into local area spatial patterns of expenditure, with existing estimates often of insufficient resolution for informing planning decisions. We use spatial microsimulation to create an archive of expenditure datasets. This was achieved by linking socio-demographic foundations with detailed datasets on individual expenditure. Whilst initially developed to aid investigations into sociodemographic trends in the meat industry, the data have reuse potential in a number of disciplines, including public health, economics, retail geography and environmental management. The framework could be applied to other regions with appropriate data.

On stopping rules and the sex ratio at birth.

One popular stopping rule intended to increase the rate of male births is to keep having babies until the first male is born. We show that such a stopping rule does not change the sex ratio at birth when the probability p that a birth produces a male is constant across a population. We show, however, that when p varies across couples, as evidence suggests that it does in the human population, with mean around 0.515 and standard deviation 0.05, then such a stopping rule tends to favour female births and the correct rule should be to stop procreating until the first female is born. But we also show that it does not seem that such stopping rules, even if favouring male births, can account for the dramatic increase in the rate of male births registered in some countries. Most of these conclusions have appeared in some form or other in various studies, but they are scattered across the literature and are very often presented using some heavy mathematical techniques. In this paper, we try to bring together these ideas and make them more accessible by analysing these stopping rules using the simplest mathematical tools possible.

Can offspring sex ratios help to explain the endocrine effects of toxoplasmosis infection on human behaviour?

Humans infected with the parasite Toxoplasma gondii display a wide variety of abnormal behaviours, from suicide and depression to stuttering. These behaviours have been seen as so serious as to constitute a public health problem. It is not clear to what extent the parasite is a cause of, or merely a marker for, these behaviours, but there is evidence for both. Some of these behaviours are associated with changes in steroid hormones, that is, estrogen in women and testosterone in men. It is suggested here that these endocrine-related states of infected people may be better understood by studying their offspring sex ratios.

Can sex ratios at birth be used in the assessment of public health, and in the identification of causes of selected pathologies?

This paper will consist of two parts. In the first, further support is given to the proposal that offspring sex ratios (proportions male) may usefully be regarded as indicators of public health. In the second, it is shown that sex ratios may help in the identification of the causes and effects of several pathologies that seriously impinge on public health viz. autism, testicular cancer, hepatitis B and toxoplasmosis.

Functional diversity and community assembly of river invertebrates show globally consistent responses to decreasing glacier cover.

Global change threatens invertebrate biodiversity and its central role in numerous ecosystem functions and services. Functional trait analyses have been advocated to uncover global mechanisms behind biodiversity responses to environmental change, but the application of this approach for invertebrates is underdeveloped relative to other organism groups. From an evaluation of 363 records comprising >1.23 million invertebrates collected from rivers across nine biogeographic regions on three continents, consistent responses of community trait composition and diversity to replicated gradients of reduced glacier cover are demonstrated. After accounting for a systematic regional effect of latitude, the processes shaping river invertebrate functional diversity are globally consistent. Analyses nested within individual regions identified an increase in functional diversity as glacier cover decreases. Community assembly models demonstrated that dispersal limitation was the dominant process underlying these patterns, although environmental filtering was also evident in highly glacierized basins. These findings indicate that predictable mechanisms govern river invertebrate community responses to decreasing glacier cover globally.

Offspring sex ratio: Coital rates and other potential causal mechanisms.

In recent years, scientists have begun to pay serious attention to the hypothesis that human parental coital rates around the time of conception causally influences the sexes of subsequent births. In this paper, the grounds of the argument are outlined. The point is important because, if the hypothesis were credible, it can potentially explain one of the best established (and otherwise unexplained) epidemiological features of sex ratio at birth - its rises during and just after World Wars 1 and 2 insofar as increased coital rates increase the ratio. Moreover, the greater the understanding of the variations of sex ratio at birth, the greater will be the understanding of the causes of those selected diseases associated with unusual sex ratios at birth (testicular cancer, hepatitis B, Toxoplasma gondii, and, perhaps, prostatic cancer).