Role of Vaspin in Human Eating Behaviour

Objective

The adipokine vaspin (visceral adipose tissue derived serine protease inhibitor, serpinA12) follows a meal-related diurnal variation in humans and intracerebroventricular vaspin administration leads to acutely reduced food intake in db/db mice. We therefore hypothesized that vaspin may play a role in human eating behaviour.

Materials and Methods

We measured serum vaspin concentrations in 548 subjects from a self-contained population of Sorbs (Germany) who underwent detailed metabolic testing including eating behaviour assessments using the three-factor eating questionnaire. In addition, genetic variation within vaspin was assessed by genotyping 28 single nucleotide polymorphisms (SNPs) in all study subjects.

Results

Serum vaspin concentrations correlated positively with restraint, disinhibition and hunger (all P<0.05), although the correlations did not withstand further adjustments for age, gender and BMI (all P>0.05). Independent of observed correlations, genetic variants in vaspin were associated with serum vaspin levels but showed no significant association with any of the eating behaviour phenotypes after accounting for multiple testing (P≥0.05 after adjusting for age, gender and BMI).

Conclusion

Our data suggest that serum vaspin concentrations might modulate human eating behaviour, which does not seem to be affected by common genetic variation in vaspin.     

A Model for Evaluating Time Constraints on Short-term Reproductive Success in Altricial Birds

SYNOPSIS. We develop a simple single dimension model incorporatingthe time and energy commitments of breeding altricial birdsin an effort to understand the evolutionary constraints on parentalcare. We chose time as the dimension of preference, becauseit is a naturally bounded constraint, e.g., length of day orbreeding season. The utility of the model was evaluated by comparingsimulations of time allocation of various breeding scenariosfor the European starling (Sturnus vulgaris) to field data.The structure of the model may prove useful in determining theevolutionary constraints on parental care imposed by the developmentalpattern of chicks.     

半圈养条件下白唇鹿行为时间分配及活动规律的研究

白唇鹿 (Cervus albirostris)是我国青藏高原特有种 ,在鹿类进化史上极其重要。因其药用价值很高 ,几十年来捕杀现象严重 ,数量大为减少 ,濒于灭绝 ,1 988年被列为国家一级保护动物 [13 ] 。目前白唇鹿分布在 2 9°～ 40°N,92°～ 1 0 2°E的区域内[1] 。它们主要活动于海拔 350 0～ 50 0 0 m之间的高寒半荒漠草原 ,高山草甸草原和亚高山灌丛草原 [7] 。国内对白唇鹿的研究 ,涉及到食性[7,11] 、繁殖[3～ 5] 、形态、生态地理分布[6] 等 ,而对白唇鹿非发情期行为时间分配尚无报道。 1 998年 3～ 4月我们在上海野生动物园对其进行了专题研…     

Circadian and Ultradian Time Patterns in Human Behaviour: Part 1: Activity Monitoring of Families from Prepartum to Postpartum

Time patterns of activity-rest rhythms during and after pregnancy are increasingly recognised as important factors for the well-being and health of young families. This longitudinal study examined activity-rest patterns of couples during late pregnancy and subsequently the alterations in the periodic structure of parental and neonatal time patterns during the first four months after birth. Part I concentrates on the effects of late pregnancy and birth to the mother's rest-activity patterns and those of the father and, after birth, what time pattern the infant developed. Part II attempts to clarify how activity patterns of the entire family agree or disagree with each other and investigates how the infant synchronises with the environment that includes the process of parent-infant interaction. Activity data of, so far, seven families (father, mother and child) were continuously recorded using non-invasive Actiwatch units. Recordings of parental activity started at the beginning of the 37th week of gestation, and were continued in parallel with the infants' recordings in three series of three weeks each until four months after birth: 1st to 3rd week, 7th to 9th week and 13th to 15th week of life. In a standardised diary, record was kept of household routines, parental activities, type of feeding, initiation of sleep or waking up. Activity data of seven non-pregnant women were collected and used as a control. Irregular nocturnal activity epochs occurred frequently in pregnant women and were absent in non-pregnant women. Period lengthenings and shortenings of the circadian rhythms appeared in both parents from prepartum to postpartum. Activity at night increased from prepartum to postpartum in mothers and fathers. Three infants showed a marked circadian rhythm between day 3 and 14 after birth. All seven infants showed a predominant circadian rhythm between day 8 and 19 after birth. The onset of daytime activity of mothers and their infants corresponded well to each other. Postpartum frequency spectra of parents and child always had some ultradian components in common. Time patterns of activity-rest rhythms of couples and parents are shown to be altered during and after pregnancy and we suggest that the infants' adaptation to the environment begins during the first week that includes the process of mother-infant interaction.     

Circadian and Ultradian Time Patterns in Human Behaviour: Part 1: Activity Monitoring of Families from Prepartum to Postpartum

Time patterns of activity-rest rhythms during and after pregnancy are increasingly recognised as important factors for the well-being and health of young families. This longitudinal study examined activity-rest patterns of couples during late pregnancy and subsequently the alterations in the periodic structure of parental and neonatal time patterns during the first four months after birth. Part I concentrates on the effects of late pregnancy and birth to the mother's rest-activity patterns and those of the father and, after birth, what time pattern the infant developed. Part II attempts to clarify how activity patterns of the entire family agree or disagree with each other and investigates how the infant synchronises with the environment that includes the process of parent-infant interaction. Activity data of, so far, seven families (father, mother and child) were continuously recorded using non-invasive Actiwatch units. Recordings of parental activity started at the beginning of the 37th week of gestation, and were continued in parallel with the infants' recordings in three series of three weeks each until four months after birth: 1st to 3rd week, 7th to 9th week and 13th to 15th week of life. In a standardised diary, record was kept of household routines, parental activities, type of feeding, initiation of sleep or waking up. Activity data of seven non-pregnant women were collected and used as a control. Irregular nocturnal activity epochs occurred frequently in pregnant women and were absent in non-pregnant women. Period lengthenings and shortenings of the circadian rhythms appeared in both parents from prepartum to postpartum. Activity at night increased from prepartum to postpartum in mothers and fathers. Three infants showed a marked circadian rhythm between day 3 and 14 after birth. All seven infants showed a predominant circadian rhythm between day 8 and 19 after birth. The onset of daytime activity of mothers and their infants corresponded well to each other. Postpartum frequency spectra of parents and child always had some ultradian components in common. Time patterns of activity-rest rhythms of couples and parents are shown to be altered during and after pregnancy and we suggest that the infants' adaptation to the environment begins during the first week that includes the process of mother-infant interaction.     

The Contribution of Social Behaviour to the Transmission of Influenza A in a Human Population

Variability in the risk of transmission for respiratory pathogens can result from several factors, including the intrinsic properties of the pathogen, the immune state of the host and the host''s behaviour. It has been proposed that self-reported social mixing patterns can explain the behavioural component of this variability, with simulated intervention studies based on these data used routinely to inform public health policy. However, in the absence of robust studies with biological endpoints for individuals, it is unclear how age and social behaviour contribute to infection risk. To examine how the structure and nature of social contacts influenced infection risk over the course of a single epidemic, we designed a flexible disease modelling framework: the population was divided into a series of increasingly detailed age and social contact classes, with the transmissibility of each age-contact class determined by the average contacts of that class. Fitting the models to serologically confirmed infection data from the 2009 Hong Kong influenza A/H1N1p pandemic, we found that an individual''s risk of infection was influenced strongly by the average reported social mixing behaviour of their age group, rather than by their personal reported contacts. We also identified the resolution of social mixing that shaped transmission: epidemic dynamics were driven by intense contacts between children, a post-childhood drop in risky contacts and a subsequent rise in contacts for individuals aged 35–50. Our results demonstrate that self-reported social contact surveys can account for age-associated heterogeneity in the transmission of a respiratory pathogen in humans, and show robustly how these individual-level behaviours manifest themselves through assortative age groups. Our results suggest it is possible to profile the social structure of different populations and to use these aggregated data to predict their inherent transmission potential.     

Rhythmic Behaviour of W. Bancrofti Microfilaraemia in Human Population at Raipur

The temporal dynamics of microfilariae (mf) in human blood, and the biting activity and mf density in the vector were studied. Finger-prick blood samples (in duplicate) were collected from 14 microfilaraemic subjects at two-hourly intervals over a single 24-hour timescale. Samples were taken from 39 subjects at 22:00 in the first week of every month for a period of 17 consecutive months. The blood slides were dried, stained and examined for presence of microfilariae. Data were analyzed with cosinor rhythmometry. A statistically validated circadian rhythm was detected in mf density in 86% of the microfilaraemic subjects. For the circannual rhythm, the peak timing for microfilariae density was recorded in July, although the spread of the peak between subjects was quite wide, extending between May 17 and September 07. In a separate study, temporal variations in biting activity, mf density in the vector and in human blood were studied. The dynamics of parasite transmission were found to be sequential, with the peaks in the circadian rhythms appearing in the order: mf in human blood, biting activity and mf density in the vector. The biting periodicity appeared to be much more stable in all subjects; the peak appeared at 02:37 with a range between 00:39 and 03:22. The peak in mf frequency was earlier by 3 hours and 25 minutes, whereas the peak in mf frequency in the vector was later by about 2 hours 4 minutes. The observed synchronization between the rhythms of vector and host appears to be essential for effective transmission of diseases. Therefore, the application of chronobiologic principles may have a bearing in the success and failure of any future strategies aimed at the prevention, cure and management of filariasis.     

Circadian Time Structure of Cardiovascular Characteristics in Human Pregnancy

Conventional time-unspecified single measurements of blood pressure and heart rate may be misleading because they may be influenced, among other factors, by the patient's emotional state, position, diet, and external stimuli. All of these effects depend on the stages of a (mathematical) spectrum of rhythms and trends with age. The evaluation of predictable variability in blood pressure and heart rate by (a) the use of fully ambulatory devices, and (b) chronobiologic data processing, assesses early cardiovascular disease risk, e.g., in pregnancy. We have used this approach to quantify changes in 24-h synchronized (circadian) characteristics of cardiovascular variables in two consecutive pregnancies of a clinically healthy woman. Blood pressure and heart rate were automatically monitored, with few interruptions, at I-h intervals, each time for at least 48 consecutive h, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of those circulatory variables were computed for each single day of measurement by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian-rhythm-adjusted means and amplitudes with gestational age. In both pregnancies, the predictable variability of the circadian-rhythm-adjusted mean of blood pressure can be approximated by a second-order polynomial model on gestational age: a steady linear decrease in systolic, diastolic, and mean arterial blood pressure up to the 22nd week of pregnancy is followed by an increase in blood pressure up to the day of delivery. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure and heart rate and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.     

Circadian Time Structure of Cardiovascular Characteristics in Human Pregnancy

Conventional time-unspecified single measurements of blood pressure and heart rate may be misleading because they may be influenced, among other factors, by the patient's emotional state, position, diet, and external stimuli. All of these effects depend on the stages of a (mathematical) spectrum of rhythms and trends with age. The evaluation of predictable variability in blood pressure and heart rate by (a) the use of fully ambulatory devices, and (b) chronobiologic data processing, assesses early cardiovascular disease risk, e.g., in pregnancy. We have used this approach to quantify changes in 24-h synchronized (circadian) characteristics of cardiovascular variables in two consecutive pregnancies of a clinically healthy woman. Blood pressure and heart rate were automatically monitored, with few interruptions, at I-h intervals, each time for at least 48 consecutive h, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of those circulatory variables were computed for each single day of measurement by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian-rhythm-adjusted means and amplitudes with gestational age. In both pregnancies, the predictable variability of the circadian-rhythm-adjusted mean of blood pressure can be approximated by a second-order polynomial model on gestational age: a steady linear decrease in systolic, diastolic, and mean arterial blood pressure up to the 22nd week of pregnancy is followed by an increase in blood pressure up to the day of delivery. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure and heart rate and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.     

Effect of Short-term Dry Immersion on Proteolytic Signaling in the Human Soleus Muscle

We analyzed the signaling processes initiating proteolytic events in the human soleus muscle during short-term exposure under the non-weight-bearing conditions. Dry immersion (DI) was used to induce weight deprivation in the m. soleus for 3 days. Western blotting was used to determine the level of insulin receptor substrate 1 (IRS-1), total and phosphorylated neuronal NO synthase (nNOS), and adenosine monophosphate-activated protein kinase (AMPK), which control the anabolic and catabolic signaling pathways, and the level of cytoskeletal protein desmin and Са²⁺-activated protease calpain. By day 3 of DI, calpain- dependent proteolysis manifests itself by reductions in both the total content and level of nNOS phosphorilation. The rate of AMPK phosphorylation was significantly decreased.     

Sexual Selection of Human Cooperative Behaviour: An Experimental Study in Rural Senegal

Human cooperation in large groups and between non-kin individuals remains a Darwinian puzzle. Investigations into whether and how sexual selection is involved in the evolution of cooperation represent a new and important research direction. Here, 69 groups of four men or four women recruited from a rural population in Senegal played a sequential public-good game in the presence of out-group observers, either of the same sex or of the opposite sex. At the end of the game, participants could donate part of their gain to the village school in the presence of the same observers. Both contributions to the public good and donations to the school, which reflect different components of cooperativeness, were influenced by the sex of the observers. The results suggest that in this non-Western population, sexual selection acts mainly on men’s cooperative behaviour with non-kin, whereas women’s cooperativeness is mainly influenced by nonsexual social selection.     

The use of Constant Routines in Unmasking the Endogenous Component of Human Circadian Rhythms

A major problem in the study of the internal clock(s) that drives human circadian rhythms is that due to the effect produced by rhythmicity of habits and external influences ('masking'). A particularly potent factor in this respect is the sleep-wake cycle. It is anomalous that, even though this masking influence is widely accepted, most studies of circadian rhythmicity have been performed in the presence of such interferences.

A protocol is described, the constant routine, by which these exogenous influences can be minimized, thereby enabling a closer scrutiny of the internal clock(s) to be made. An account is given of the different circumstances in which the constant routines have been used together with the results derived from such studies. Briefly, they indicate that nychthemeral studies can give misleading information about the rate of adjustment of the internal clock to various manipulations, e.g. time-zone transition, shift work.

In addition, future studies making use of constant routines are described, in particular those which might enable the presence of more than one internal clock to be established.     

A Model of Patch Visit Behaviour in Fish

The patch visit or sampling behaviour of fish is studied over a 15 day period. The experimental setup consists of three connected patches between which movement is automatically registered. Using an integer-valued time series model we find a diel effect on the probability to stay in one of the patches.     

The use of Constant Routines in Unmasking the Endogenous Component of Human Circadian Rhythms

A major problem in the study of the internal clock(s) that drives human circadian rhythms is that due to the effect produced by rhythmicity of habits and external influences (‘masking’). A particularly potent factor in this respect is the sleep-wake cycle. It is anomalous that, even though this masking influence is widely accepted, most studies of circadian rhythmicity have been performed in the presence of such interferences.

A protocol is described, the constant routine, by which these exogenous influences can be minimized, thereby enabling a closer scrutiny of the internal clock(s) to be made. An account is given of the different circumstances in which the constant routines have been used together with the results derived from such studies. Briefly, they indicate that nychthemeral studies can give misleading information about the rate of adjustment of the internal clock to various manipulations, e.g. time-zone transition, shift work.

In addition, future studies making use of constant routines are described, in particular those which might enable the presence of more than one internal clock to be established.     

Time Adaptation Shows Duration Selectivity in the Human Parietal Cortex

Although psychological and computational models of time estimation have postulated the existence of neural representations tuned for specific durations, empirical evidence of this notion has been lacking. Here, using a functional magnetic resonance imaging (fMRI) adaptation paradigm, we show that the inferior parietal lobule (IPL) (corresponding to the supramarginal gyrus) exhibited reduction in neural activity due to adaptation when a visual stimulus of the same duration was repeatedly presented. Adaptation was strongest when stimuli of identical durations were repeated, and it gradually decreased as the difference between the reference and test durations increased. This tuning property generalized across a broad range of durations, indicating the presence of general time-representation mechanisms in the IPL. Furthermore, adaptation was observed irrespective of the subject’s attention to time. Repetition of a nontemporal aspect of the stimulus (i.e., shape) did not produce neural adaptation in the IPL. These results provide neural evidence for duration-tuned representations in the human brain.     

Investigating the Endogenous Component of Human Circadian Rhythms: A Review of Some Simple Alternatives to Constant Routines

Several types of constant routine are accepted as an important means by which the endogenous component of circadian rhythms can be studied. Nevertheless, they are impracticable to perform and unsuitable for routine use in many individuals. We describe a group of simple methods with which rhythms measured in normal circumstances can be dissociated into the components due to masking and the internal clock. Each method is best suited to a particular type of experimental condition. Results from a variety of protocols are analysed by these and conventional methods to assess the validity of the new methods.     

Treatment-Seeking for Tuberculosis-Suggestive Symptoms: A Reflection on the Role of Human Agency in the Context of Universal Health Coverage in Malawi

Tuberculosis (TB) is highly infectious and one of the leading killers globally. Several studies from sub-Saharan Africa highlight health systems challenges that affect ability to cope with existing disease burden, including TB, although most of these employ survey-type approaches. Consequently, few address community or patient perspectives and experiences. At the same time, understanding of the mechanisms by which the health systems challenges translate into seeking or avoidance of formal health care remains limited. This paper applies the notion of human agency to examine the ways people who have symptoms suggestive of TB respond to and deal with the symptoms vis-à-vis major challenges inherent within health delivery systems. Empirical data were drawn from a qualitative study exploring the ways in which notions of masculinity affect engagement with care, including men’s well-documented tendency to delay in seeking care for TB symptoms. The study was carried out in three high-density locales of urban Blantyre, Malawi. Data were collected in March 2011 –March 2012 using focus group discussions, of which eight (mixed sex = two; female only = three; male only = three) were with 74 ordinary community members, and two (both mixed sex) were with 20 health workers; and in-depth interviews with 20 TB patients (female = 14) and 20 un-investigated chronic coughers (female = eight). The research process employed a modified version of grounded theory. Data were coded using a coding scheme that was initially generated from the study aims and subsequently progressively amended to incorporate concepts emerging during the analysis. Coded data were retrieved, re-read, and broken down and reconnected iteratively to generate themes. A myriad of problems were described for health systems at the primary health care level, centring largely on shortages of resources (human, equipment, and drugs) and unprofessional conduct by health care providers. Participants consistently pointed out how the problems could drive patients from promptly reporting symptoms at primary healthcare centres. The accounts suggest that in responding to illness symptoms including those suggestive of TB, patients navigate their options taking into cognisance past and current experiences with formal health systems. Understanding and factoring in the mediating role of such ‘agency’ is critical when implementing efforts to promote timely response to TB-suggestive symptoms.