A new approach to evaluate gamma-ray measurements

Misunderstandings about the term random samples its implications may easily arise. Conditions under which the phases, obtained from arrival times, do not form a random sample and the dangers involved are discussed. Watson's U sup 2 test for uniformity is recommended for light curves with duty cycles larger than 10%. Under certain conditions, non-parametric density estimation may be used to determine estimates of the true light curve and its parameters

Chandra and RXTE studies of the X-ray/gamma-ray millisecond pulsar PSR J0218+4232

We report on high-resolution spatial and timing observations of the millisecond pulsar PSR J0218+4232 performed with the Chandra X-ray Observatory (CXO) and the Rossi X-ray Timing Explorer (RXTE). With these observations we were able to study a) the possible spatial extent at X-ray energies of the DC source coincident with PSR J0218+4232 in detail (CXO), b) the relative phasing between the X-ray, radio and gamma-ray profiles (CXO and RXTE) and c) the spectral properties at energies beyond 10 keV (RXTE). We found no indications for extended emission at X-ray energies down to ~ 1 arcsec scales and confirmed the presence of a point-like DC-component. The 2 non-thermal pulses in the X-ray profile are found to be aligned with 2 of the 3 pulses visible at radio-frequencies and more importantly with the two gamma-ray pulses seen in the EGRET 100-1000 MeV pulse profile. The latter reduces now the random occurrence probability for the detected gamma-ray signal to ~ 1.E-6, which corresponds to a 4.9 sigma detection significance.Comment: 8 pages,7 figures, accepted for publication in Adv Sp Res: Proceedings of the 34th COSPAR Scientific Assembly held in Housto

Can an evolutionary perspective shed light on maternal abuse of children?

Although the theory of evolution lies at the heart of contemporary biology, its influence on the study of child psychology and psychiatry has been limited. In earlier work we have argued that evolutionary thinking has much of value for clinicians. Here, we explore the possible significance of evolutionary theory for understanding child abuse by mothers, particularly neglect, emotional abuse and physical abuse. We draw on the research of anthropologists, primatologists and evolutionary theorists to make predictions about the environmental circumstances under which one would expect such abuse to be more prevalent. We discuss how in modern, Western cultures there is less understanding of the circumstances that may influence, even predispose, a mother to limit her emotional and material commitment to an infant or child. We use four short vignettes of clinical cases and one longer case description to illustrate the insights offered to clinicians by an evolutionary approach. We see our work both as contributing to greater understanding of these matters and as facilitating more compassionate models of care and intervention for women in such circumstances

Important complications of chronic kidney disease

The complications of chronic kidney disease (CKD) are dyslipidaemia, hyperkalaemia, metabolic acidosis, anaemia, and bone and mineral disorders. Dyslipidaemia may be treated with low-density lipoprotein lowering agents. Statins are ineffective in stages 4 and 5 CKD, but are indicated for preventing the progression of disease in the earlier stages. Chronic acidosis has recently been shown to be a risk factor in the progression of CKD renal dysfunction. Therefore, treatment is mandatory. Practically, this should  consist of 1 - 2 heaped teaspoons of sodium bicarbonate 2 - 3 times per day, which is an inexpensive and safe therapy that does not raise the blood pressure in spite of the increased sodium level. Target levels of haemoglobin, according to international guidelines, are between 10 g/dL and 12 g/dL. The serum phosphate level is raised in stage 4 CKD, and especially in stage 5 CKD, which is associated with coronary carotid and other vascular calcifications and may result in ischaemic heart disease, myocardial infarction and stroke. A raised parathyroid hormone level (secondary hyperparathyroidism) is also a major risk factor for cardiovascular disease and is associated with increased hypertension and resistance to the treatment of CKD-associated anaemia

The snacking habits of white preschool ·children

Three-day estimated dietary records were kept for 194 white 3- and 4-year-old children to deterMine and evaluate the extent, nature and quality of their snacking. All but 1 child ate between meals, with morning and afternoon snacking being favoured in terms of frequency and quantity. Soft drinks were .consumed most frequently, followed by fresh fruits and fruit juices, sweets and chocolates, milk and sugar. Between-meal eating contributed more than one-third of the average day's energy and approximately one-quarter of most vitamins and minerals to the children's diets. Foods eaten between meals were, however, significantly less nutrient-dense than mealtime foods. Non-basic foods supplied more energy to the diet than _ any of the five basic food groups, but minimal quantities of micronutrients. Sugar consumption, mostly in the form of sugary foods and drinks, was high, but was not consumed exclusively between meals. Such children should be encouraged to make more use of basic commodities, particularly when snacking

Movement patterns and athletic performance of leopards in the Okavango Delta

Although leopards are the most widespread of all the big cats and are known for their adaptability, they are elusive and little is known in detail about their movement and hunting energetics. We used high-resolution GPS/IMU (inertial measurement unit) collars to record position, activity and the first high-speed movement data on four male leopards in the Okavango Delta, an area with high habitat diversity and habitat fragmentation. Leopards in this study were generally active and conducted more runs during the night, with peaks in activity and number of runs in the morning and evening twilight. Runs were generally short (less than 100 m) and relatively slow (maximum speed 5.3 m s−1, mean of individual medians) compared to other large predators. Average daily travel distance was 11 km and maximum daily travel distance was 29 km. No direct correlation was found between average daily temperature and travel distance or between season and travel distance. Total daily energy requirements based on locomotor cost and basal metabolic rate varied little between individuals and over time. This study provides novel insights into movement patterns and athletic performance of leopards through quantitative high-resolution measurement of the locomotor, energetic, spatial and temporal movement characteristics. The results are unbiased by methodological and observational limitations characteristic of previous studies and demonstrate the utility of applying new technologies to field studies of elusive nocturnal species

The Effect of Planting Date on the Dry Matter Production of Italian and Westerwolds Ryegrass in the Southern Cape of South Africa

Perennial pasture species such as lucerne (Medicago sativa), kikuyu (Pennisetum clandestinum), perennial ryegrass (Lolium perenne) and perennial clovers (Trifolium spp.) make an important contribution to the fodder flow programmes for dairy production in the southern Cape. One of the main challenges when these species make up the primary pasture base within a pasture system is the mutually low growth rates during winter (Van Heerden et al., 1989; Swanepoel et al., 2014). In order to bridge pasture shortages during the critical winter months, producers establish annual Italian (Lolium multiflorum var. italicum) and Westerwolds ryegrass (L. multiflorum var. westerwoldicum) either as pure swards, mixtures or over-sown it into perennial pastures. The production potential and seasonal growth of annual ryegrass varieties are affected by climate and may not follow the same pattern of production as in other regions. The aim of this study was to determine the production potential of Italian and Westerwolds ryegrass planted at different planting dates in the southern Cape of South Africa

Bounding Helly numbers via Betti numbers

We show that very weak topological assumptions are enough to ensure the existence of a Helly-type theorem. More precisely, we show that for any non-negative integers $b$ and $d$ there exists an integer $h(b,d)$ such that the following holds. If $\mathcal F$ is a finite family of subsets of $\mathbb R^d$ such that $\tilde\beta_i\left(\bigcap\mathcal G\right) \le b$ for any $\mathcal G \subsetneq \mathcal F$ and every $0 \le i \le \lceil d/2 \rceil-1$ then $\mathcal F$ has Helly number at most $h(b,d)$. Here $\tilde\beta_i$ denotes the reduced $\mathbb Z_2$-Betti numbers (with singular homology). These topological conditions are sharp: not controlling any of these $\lceil d/2 \rceil$ first Betti numbers allow for families with unbounded Helly number. Our proofs combine homological non-embeddability results with a Ramsey-based approach to build, given an arbitrary simplicial complex $K$, some well-behaved chain map $C_*(K) \to C_*(\mathbb R^d)$.Comment: 29 pages, 8 figure

On the multiple Borsuk numbers of sets

The Borsuk number of a set S of diameter d >0 in Euclidean n-space is the smallest value of m such that S can be partitioned into m sets of diameters less than d. Our aim is to generalize this notion in the following way: The k-fold Borsuk number of such a set S is the smallest value of m such that there is a k-fold cover of S with m sets of diameters less than d. In this paper we characterize the k-fold Borsuk numbers of sets in the Euclidean plane, give bounds for those of centrally symmetric sets, smooth bodies and convex bodies of constant width, and examine them for finite point sets in the Euclidean 3-space.Comment: 16 pages, 3 figure

Extending the geographical distribution of Side-striped Jackal, Lupulella adusta (Sundevall, 1847) (Carnivora, Canidae), in South Africa

Side-striped Jackal, Lupulella adusta (Sundevall, 1847), occurs in a vast area within sub-Saharan Africa. In South Africa, the current geographical distribution is limited to eastern coastal regions. Recent sightings from north-central areas of the country suggest a wider geographical distribution. Here we report on 5,130 confirmed, repeated detections of Side-striped Jackal. Of these, 3,625 captures were from 471 new locations not previously recorded in the scientific literature, thereby expanding their current geographical distribution. These new records were captured in 33 vegetation types, including the forest and grassland biomes where they are not commonly detected