To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
A reformulation of the Social Brain Theory of schizophrenia is proposed that contends that schizophrenia is a novel human phenomenon that arose following the establishment of large permanent human settlements and the abandonment of the hunter-gatherer way of life. It is contended that the blurring of the demarcation between ingroup and outgroup membership and living in close proximity to strangers is a stressor that leads to perturbation in the development of the social brain in vulnerable individuals leading to the syndrome of schizophrenia. Contrary to previous authors who have considered schizophrenia to be an inherently human condition that has existed throughout human history we suggest that schizophrenia is a relatively recent phenomenon and that the vulnerability to it remained hidden amongst hunter-gatherers. Hence, we contend that schizophrenia is the result of a mismatch between the post-Neolithic human social environment and the design of the social brain. The importance of the distinction between ingroup and outgroup membershipin human evolutionary history lies at the heart of inter-group conflict, violence and xenophobia. This formulation explains a range of epidemiological findings on schizophrenia related to the risk of migration and urbanisation. The present hypothesis can therefore, account for a range of disparate findings regarding schizophrenia that have thus far defied explanation by other extant theories. However, as this formulation claims to have identified the ultimate causation of schizophrenia the hypothesis does not specify the proximate mechanisms that lead to it. We conclude with a number of testable and refutable predictions.
Women may experience a variety of fears in association with pregnancy and childbirth. Fear can cause significant problem during childbirth and post partum. Fear has been associated with more reported pain in childbirth a longer first and second stage of labor and dissatisfaction with the childbirth experience.
The purpose of this study was to describe the fear and causes associated with pregnancy and childbirth among Kurdish women in Iran.
Twenty-two Kurdish pregnant women in Sanandaj (the capital of Kurdistan province in the West of Iran) were interviewed during third trimester of their pregnancy. A qualitative design was chosen and grounded theory was used for data analysis.
All women expressed at least some fears associated with pregnancy and/or childbirth. Women's fears were related to baby's well-being, process and procedure during labor and childbirth, family life, criticism of husband's family, and attitudes of hospital personnel. The reasons for their fears included: previous negative experiences, knowledge, maternity environment and hospital personnel, baby gender and financial situation.
The findings suggest that childbirth education and health care services requiring more attention and exploration. The findings also highlight the need for a careful review of the existing labor and delivery units and procedures. Midwives need further training in how to meet and support pregnant women with fear related to pregnancy and childbirth.
Competing theories on the aetiology of eating disorders originate from a diverse set of disciplines. One such discipline is Evolutionary Psychology which assumes that the human mind has been shaped by natural and sexual selection. Most evolutionary theories on eating disorders limit themselves to the causation of anorexia nervosa only. The Sexual Competition Hypothesis (SCH), based on the Darwinian theory of sexual selection, provides an explanatory framework for the whole spectrum of eating disorders. It contends that intense female intrasexual competition (ISC) is the ultimate cause of eating disorders. The SCH explains the phenomenon of the pursuit of thinness as an adaptation to ISC in the modern environment. It argues that eating disorders are pathological phenomena that arise from the mismatch between the modern environment and the inherited female adaptations for ISC.
To test predictions from a novel evolutionary hypothesis for eating disorders.
i) To examine the relationship between disordered eating behaviour (DEB) and ISC in a sample of female undergraduates.
ii) To establish whether there is any relationship between DEB and Life History (LH) strategy.
A group of 206 female undergraduates were recruited. A structural equation model was constructed to analyse the data.
ISC for mates was significantly associated with DEB, as predicted by the SCH. DEB was found to be predicted by fast LH strategy, which was only partially mediated by the SCH.
The results of this study are supportive of the SCH and justify research on a clinical sample.
A new planar multiple-input–multiple-output (MIMO) antenna for ultra wideband (UWB) applications is presented. The proposed antenna operates over the frequency band from 3.1 to 10.6 GHz and it consists of two identical circular monopoles on an FR4 substrate. The wide isolation is achieved through a novel planar decoupling structure that is being inserted between the dual antennas. Moreover, a center slot is etched on the common ground to further increase isolation. The effectiveness of the decoupling structure is analyzed, and performance study has been performed to investigate the mutual coupling reduction. A good isolation of more than 31 dB has been achieved through the entire UWB band (more than 12 dB improvement over the reference antenna). The proposed UWB antenna with and without the wideband decoupling structure has been investigated and verified both numerically and experimentally. The measurement results of the proposed UWB–MIMO antenna are in good agreement with the simulation results. The proposed UWB antenna has been compared with previous works regarding antenna size, geometric complexity, bandwidth, and isolation level. The proposed antenna has some outstanding characteristics such as a geometric simplicity, compact size, broad bandwidth, and low correlation which give the antenna an excellent diversity performance and a good candidate for UWB applications.
Documenting past changes in the East Antarctic surface mass balance is important to improve ice core chronologies and to constrain the ice-sheet contribution to global mean sea-level change. Here we reconstruct past changes in the ratio of surface mass balance (SMB ratio) between the EPICA Dome C (EDC) and Dome Fuji (DF) East Antarctica ice core sites, based on a precise volcanic synchronization of the two ice cores and on corrections for the vertical thinning of layers. During the past 216 000 a, this SMB ratio, denoted SMBEDC/SMBDF, varied between 0.7 and 1.1, being small during cold periods and large during warm periods. Our results therefore reveal larger amplitudes of changes in SMB at EDC compared with DF, consistent with previous results showing larger amplitudes of changes in water stable isotopes and estimated surface temperature at EDC compared with DF. Within the last glacial inception (Marine Isotope Stages, MIS-5c and MIS-5d), the SMB ratio deviates by up to 0.2 from what is expected based on differences in water stable isotope records. Moreover, the SMB ratio is constant throughout the late parts of the current and last interglacial periods, despite contrasting isotopic trends.
This study aimed to determine the relationship between quality of life and satisfaction with care among cancer patients in palliative care in Saudi Arabia.
A total of 130 palliative cancer patients were invited to participate in our cross-sectional study. Patients were recruited from a large tertiary hospital within the Ministry of Health in Saudi Arabia. All eligible participants answered a three-part questionnaire that included demographic data and the validated European Organization for Research and Treatment of Cancer (EORTC QLQ–C15–PAL) and (EORTC IN-PATSAT32) questionnaires.
Participants were mostly female (103/130, 79%) and married (93/130, 71%), and more than half had breast cancer (69/130, 53%). They were between 17 and 86 years of age (mean = 46.7, SD = 16.50). The correlation test showed that the relationship with physical function was weak, while emotional function and global health status had a moderate relationship with general satisfaction (r = 0.21, p < 0.01; r = 0.32, p < 0.001; r = 0.26, p < 0.01, respectively). Our results suggest that emotional function is the more important factor in predicting satisfaction with care among palliative cancer patients. An increase in emotional function leads to increased general satisfaction.
Significance of results:
The emotional function of palliative cancer patients was more closely associated with overall satisfaction with care than physical function or global health status. All palliative care team members are thus required to provide adequate psychosocial support. It is recommended that interdisciplinary and collaborative approaches be integrated in palliative care of cancer patients.
In traditional transit timing variations (TTVs) analysis of multi-planetary systems, the individual TTVs are first derived from transit fitting and later modelled using n-body dynamic simulations to constrain planetary masses. We show that fitting simultaneously the transit light curves with the system dynamics (photo-dynamical model) increases the precision of the TTV measurements and helps constrain the system architecture. We exemplify the advantages of applying this photo-dynamical model to a multi-planetary system found in K2 data very close to 3:2 mean motion resonance, K2-19. In this case the period of the larger TTV variations (libration period) is much longer (>1.5 years) than the duration of the K2 observations (80 days). However, our method allows to detect the short period TTVs produced by the orbital conjunctions between the planets that in turn permits to uniquely characterise the system. Therefore, our method can be used to constrain the masses of near-resonant systems even when the full libration curve is not observed.
The transport equation for the mean turbulent energy dissipation rate
along the centreline of a fully developed channel flow is derived by applying the limit at small separations to the two-point budget equation. Since the ratio of the isotropic energy dissipation rate to the mean turbulent energy dissipation rate
is sufficiently close to 1 on the centreline, our main focus is on the isotropic form of the transport equation. It is found that the imbalance between the production of
due to vortex stretching and the destruction of
caused by the action of viscosity is governed by the diffusion of
by the wall-normal velocity fluctuation. This imbalance is intrinsically different from the advection-driven imbalance in decaying-type flows, such as grid turbulence, jets and wakes. In effect, the different types of imbalance represent different constraints on the relation between the skewness of the longitudinal velocity derivative
and the destruction coefficient
of enstrophy in different flows, thus resulting in non-universal approaches of
towards a constant value as the Taylor microscale Reynolds number,
, increases. For example, the approach is slower for the measured values of
along either the channel or pipe centreline than along the axis in the self-preserving region of a round jet. The data for
collected in different flows strongly suggest that, in each flow, the magnitude of
is bounded, the value being slightly larger than 0.5.
The supposed universality of the incidence and prevalence of schizophrenia has been seriously challenged. It is now widely accepted that the life-time prevalence and incidence of this disorder vary considerably in time and place. As a result, there has been renewed interest in environmental causation of schizophrenia. There are few extant formulations that have successfully integrated the available new evidence into a coherent theory for its causation. The outgroup intolerance hypothesis is an attempt to integrate this evidence. It proposes that schizophrenia is the result of a mismatch between the social brain as shaped by evolution and the new social conditions of the post-neolithic. The hypothesis can provide an explanation for (i) the higher risk to migrants, (ii) the ethnic density phenomenon, (iii) the increased risk to individuals who have grown up in cities and (iv) the putative low risk in hunter-gatherer societies. Evidence is presented from a range of disciplines and sources including epidemiology, psychopathology, social psychology and clinical trials in support of this hypothesis. A range of testable predictions follow from the hypothesis.
Ten ice-sheet models are used to study sensitivity of the Greenland and Antarctic ice sheets to prescribed changes of surface mass balance, sub-ice-shelf melting and basal sliding. Results exhibit a large range in projected contributions to sea-level change. In most cases, the ice volume above flotation lost is linearly dependent on the strength of the forcing. Combinations of forcings can be closely approximated by linearly summing the contributions from single forcing experiments, suggesting that nonlinear feedbacks are modest. Our models indicate that Greenland is more sensitive than Antarctica to likely atmospheric changes in temperature and precipitation, while Antarctica is more sensitive to increased ice-shelf basal melting. An experiment approximating the Intergovernmental Panel on Climate Change’s RCP8.5 scenario produces additional first-century contributions to sea level of 22.3 and 8.1 cm from Greenland and Antarctica, respectively, with a range among models of 62 and 14 cm, respectively. By 200 years, projections increase to 53.2 and 26.7 cm, respectively, with ranges of 79 and 43 cm. Linear interpolation of the sensitivity results closely approximates these projections, revealing the relative contributions of the individual forcings on the combined volume change and suggesting that total ice-sheet response to complicated forcings over 200 years can be linearized.
Cluster dynamics (CD) modeling has been used to estimate the long-term evolution of point defect (PD) clusters. However, previous studies have often simplified the governing equations by assuming the maximum size of mobile self-interstitial atom (SIA) clusters and by ignoring the one-dimensional (1D) reaction kinetics of SIA loops. They have also conducted parameter fittings, such as the clustered fraction and the maximum size of clusters produced by collision cascade, to reproduce experimental data. In this study, in addition to modeling the 1D motion of SIA loops in the framework of the production bias model (PBM), reaction rates associated with carbon impurity atoms present in alpha iron were formulated to consider the trapping effect of one-dimensionally migrating SIA loops by a vacancy-carbon (V-C) complex that was shown to have strong bindings with SIA loops by previous atomistic simulations. Calculations results for neutron-irradiated alpha iron showed that the developed CD model can successfully reproduce the saturation trend of the number density of immobile SIA loops in contrast to the prediction using a model without the trapping effect.
We have prepared 2% Al doped ZnO (AZO) thin films on SrTiO3 and Al2O3 substrates by Pulsed Laser Deposition (PLD) technique at various deposition temperatures (Tdep = 300 °C – 600 °C). Transport and thermoelectric properties of AZO thin films were studied in low temperature range (300 K - 600 K). AZO/STO films present superior performance respect to AZO/Al2O3 films deposited at the same temperature, except for films deposited at 400 °C. Best film is the fully c-axis oriented AZO/STO deposited at 300 °C, with electrical conductivity 310 S/cm, Seebeck coefficient -65 μV/K and power factor 0.13 × 10-3 Wm-1K-2 at 300 K. Its performance increases with temperature. For instance, power factor is enhanced up to × 10-3 Wm-1K-2 at 600 K, surpassing the best AZO film previously reported in literature.
Indoor radon surveys were carried out in some of the Arab
countries through a Coordination Research Program (CRP) organized
by the Arab Atomic Energy Agency (AAEA). The objectives of the program
aim at establishing a database on indoor radon concentration levels
in the region and investigating any anomalies, where they exist.
The approach adopted by the survey teams to achieve public participation
in accepting the radon detectors in dwellings is presented and discussed.
Most of the participants in the CRP used the passive method (CR-39
plastic detectors) for long-term radon measurements, while others
used charcoal detectors and E-Perm systems for short-term measurements.
The results of the surveys showed that radon concentration levels
in most of the dwellings were low, whilst in some old cities and
in an area close to a phosphate mine the levels were found to be
The fossil record provides an important source of data on adaptive radiations, and indeed some of the earliest theoretical insights on the nature of these radiations were made by paleontologists. Here we focus on the diverse Devonian Metacryphaeus group calmoniid trilobites, known from the Malvinokaffric Realm, which have been considered a classic example of an adaptive radiation preserved in the fossil record. We use a geometric morphometric analysis in conjunction with phylogenetic and biogeographic patterns and data on speciation rates. Using ancestral character state reconstruction during speciation events, we quantify patterns of morphological change in order to assess the role ecological and geographical factors may have played in mediating this radiation. We found no significant differences between the amount of morphological change that occurred during speciation events when ancestors and descendants were in the same area as opposed to when they occupied different areas. Further, the magnitude of morphological divergence did not change through time or with cladogenetic rank. These patterns, in conjunction with the fact that the radiation occurs in a geographically heterogeneous region subjected to repeated episodes of sea-level rise and fall, suggest that at the macroevolutionary scale this radiation may have been motivated more by phenomena that facilitated geographic isolation than by competition.
Background: The aim of the present study was to investigate the differences in the prevalence of and risk factors for elderly depression between urban and rural areas in Japan and to further understanding of the features of elderly depression.
Methods: A multistage, random sampling procedure and mailing method were used in urban and rural areas in Kumamoto Prefecture. A total of 2,152 participants aged 65 years and older were evaluated for depression using the Geriatric Depression Scale (GDS). Factors associated with depression were also examined. In order to assess the relationship between risk factors and subjective happiness, the Philadelphia Geriatric Center Morale Scale (PGC-MS) was used.
Results: Depressive symptoms were associated with living alone, being unemployed, chronic illness, sleep disturbance, suicidal ideation, financial strain, and poor social support; the risk factors for elderly depression were almost the same in the two areas. Although three factors (financial strain, work status, and PGC-MS) were significantly associated with depression in both areas on logistic regression analysis, sleep disturbance was significant only for the urban area, and poor social support was significant only for the rural area.
Conclusions: Although factors related to depression did not differ markedly between urban and rural elderly people, some risk factors differed between the two areas. Effective intervention programs for elderly depression should pay more attention to regional differences.
The surface of Ti-based bulk metallic glass (BMG) was irradiated by the femto-second laser and microgrooves were formed on the surface. The titanate nanomesh layers were fabricated on the micro-grooved BMG surface by hydrothermal-electrochemical (H-E) treatment changing the conditions of the concentration of electrolyte solution (0 and 5 M) and applying current density (0-200 mA/cm2). The bone-inducing capacity of the samples with different H-E treatment was confirmed by soaking them in a simulated body fluid for 12 days. The H-E treatment in higher concentration 5 M NaOH aq. and applying higher current density above 0.5 mA/cm2 exhibited excellent bioactivity inducing large hydroxyapatite crystallites.
In this paper, the authors present a new theory that can be applied to predetermine the value of cutoff temperature of operation (Tcutoff) of uncooled semiconductor laser diodes. Tcutoff is defined as the value of temperature of operation above which, the turn-on time delay ton of uncooled SLD will exceed the bit time interval of the injected pulse and results in an inoperable case. An analytical model is derived to represent the temperature dependence of ton. This model is used to derive an accurate one for Tcutoff and in terms of laser cavity parameters. Simulation results show that Tcutoff can be increased (improved) by increasing the injection current or biasing the uncooled SLD near threshold. The benefit of this study is that the designer could predetermine previously the requirements that should be taken into account, when considering of uncooled SLD in high-speed optical communication systems.