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Landraces (including heritage varieties) are an important agrobiodiversity resource offering considerable value as a buffer against crop failures, as a crop for niche markets, and as a source of diversity for crop genetic improvement activities underpinning future food security. Home gardens are reservoirs of landrace diversity, but some of the accessions held in them are vulnerable or threatened with extinction. Those associated with seed saving networks have added security, for example, ca. 800 varieties are stored in the Heritage Seed Library (HSL) of Garden Organic, UK. In this study, Amplified Fragment Length Polymorphisms-based genetic analysis of accessions held in the HSL was used to (a) demonstrate the range of diversity in the collection, (b) characterize accessions to aid collection management and (c) promote broader use of the collection. In total, 171 accessions were included from six crops: Vicia faba L., Pisum sativum L., Daucus carota L., Cucumis sativus L., Lactuca sativa L. and Brassica oleracea L. var. acephala (DC.) Metzq. Average expected heterozygosity ranged from 0.18 to 0.28 in D. carota; 0.02–0.18 in P. sativum; 0.05–0.18 in L. sativa; 0.15–0.26 in B. oleracea var. acephala; 0.15–0.37 in C. sativus and 0.07–0.36 in V. faba. Genetic diversity and Fst values generally reflected the breeding system and cultivation history of the different crops. Comparisons of the diversity found in heritage varieties with that found in commercial varieties did not show a consistent pattern. Principal coordinates analysis and Unweighted Pair Group Method with Arithmetic Mean cluster analysis were used to identify four potential duplicate accession pairs.
At the ANZIAM conference in Hobart in February 2018, there were several talks on the solution of Laplace problems in multiply connected domains by means of conformal mapping. It appears to be not widely known that such problems can also be solved by the elementary method of series expansions with coefficients determined by least-squares fitting on the boundary. (These are not convergent series; the coefficients depend on the degree of the approximation.) Here we give a tutorial introduction to this method, which converges at an exponential rate if the boundary data are sufficiently well-behaved. The mathematical foundations go back to Runge in 1885 and Walsh in 1929. One of our examples involves an approximate Cantor set with up to 2048 components.
Large-scale trends in planktonic foraminiferal diversity have so far been based on utilization of synoptic biostratigraphic range charts. Although this approach ensures the taxonomic consistency and quality of the data being used, it takes no formal account of any sampling biases that might exist in the fossil record. We demonstrate that the occurrence data of planktonic foraminifera, as recorded in the primary literature, are strongly biased by sampling. We do this by demonstrating that raw diversity curves derived from the land-based and deep-sea records are strikingly different, but that they each correlate with the intensity of sampling in their respective environments, and thus are ultimately controlled by the structure of the geological record in each setting. Because sampling of the Mesozoic record is best in our land record whereas sampling of the Cenozoic is best in our deep-sea record, we combine the two to generate the best-supported estimates of species and genus diversity over time from these data. We correct for sampling bias using shareholder quorum subsampling and a modeling approach. The data are then transformed to generate a range-through plot of species richness that is compared with two earlier estimates of the diversity history where comparable species-in-bin data can be recovered. No robust statistical correlation is found among the three estimates. Although differences in amplitude are to be expected, differences in the actual shape of the curve are surprising. We conclude that these differences stem from the nature of the data themselves, namely the taxonomic scheme adopted and the taxonomic coverage used.
We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure to Leptospira spp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor to Chlamydia abortus. Some sheep tested positive for antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.
Attentional impairment is a core cognitive feature of major depressive disorder (MDD) and bipolar disorder (BD). However, little is known of the characteristics of response time (RT) distributions from attentional tasks. This is crucial to furthering our understanding of the profile and extent of cognitive intra-individual variability (IIV) in mood disorders.
A computerized sustained attention task was administered to 138 healthy controls and 158 patients with a mood disorder: 86 euthymic BD, 33 depressed BD and 39 medication-free MDD patients. Measures of IIV, including individual standard deviation (iSD) and coefficient of variation (CoV), were derived for each participant. Ex-Gaussian (and Vincentile) analyses were used to characterize the RT distributions into three components: mu and sigma (mean and standard deviation of the Gaussian portion of the distribution) and tau (the ‘slow tail’ of the distribution).
Compared with healthy controls, iSD was increased significantly in all patient samples. Due to minimal changes in average RT, CoV was only increased significantly in BD depressed patients. Ex-Gaussian modelling indicated a significant increase in tau in euthymic BD [Cohen's d = 0.39, 95% confidence interval (CI) 0.09–0.69, p = 0.011], and both sigma (d = 0.57, 95% CI 0.07–1.05, p = 0.025) and tau (d = 1.14, 95% CI 0.60–1.64, p < 0.0001) in depressed BD. The mu parameter did not differ from controls.
Increased cognitive variability may be a core feature of mood disorders. This is the first demonstration of differences in attentional RT distribution parameters between MDD and BD, and BD depression and euthymia. These data highlight the utility of applying measures of IIV to characterize neurocognitive variability and the great potential for future application.
Standard acute psychiatric care in the UK is costly but problematic. Alternatives to standard in-patient wards exist, but little is known about their effectiveness, implementation and sustainability. This paper explores successful features and limitations of five residential alternative services in England and factors that facilitate or impede their initial and sustained implementation and success.
Semi-structured interviews about the functioning of six alternative services were conducted with 36 mental health professionals with good working knowledge of, and various connections with these services. A group interview with study researchers was also conducted. Data were analysed using thematic analysis.
One service did not show evidence of operating as an alternative and was excluded from further analysis. The remaining five alternatives are valued for providing a more holistic style of care than standard services that confers many perceived benefits. However, they are seen as less appropriate for compulsorily detained or highly disturbed patients, and as providing less comprehensive treatment packages than hospital settings. Factors identified as important to successful implementation and sustainability are: responding to known shortcomings in local acute care systems; balancing role clarity and adaptability; integration with other services; and awareness of the alternative among relevant local health-care providers.
Residential alternatives can play an important role in managing mental health crises. Their successful implementation and endurance depend on establishing and maintaining a valued position within local service systems. Findings contribute to bridging the gap between research evidence on the problems of standard acute care and delivering improved crisis management services.
Periodic solutions of certain one-dimensional non-autonomous differential equations are investigated (equation (1.4)); the independent variable is complex. The motivation, which is explained in the introductory section, is the connection with certain polynomial two-dimensional systems. Several classes of coefficients are considered; in each case the aim is to estimate the maximum number of periodic solutions into which a given solution can bifurcate under perturbation of the coefficients. In particular, we need to know when there is a full neighbourhood of periodic solutions. We give a number of sufficient conditions and investigate the implications for the corresponding two-dimensional systems.
are considered, where P and Q are polynomials. The question of interest is the maximum possible numberof limit cycles of such systems in terms of the degree of P and Q. An algorithm is described for determining a so-called focal basis; this can be implemented on a computer. Estimates can then be obtained for the number of small-amplitude limit cycles. The technique is applied to certain cubic systems; a class of examples with exactly five small-amplitude limit cycles is constructed. Quadratic systems are also considered.
Suppose that f: ℝ×ℂN→ℂN is holomorphic in z and continuous in t, and that Φ: ℂN×ℂN→ℂN is holomorphic. Boundary value problems of the form
are considered. The particular interest is in the structure and topological properties of the set of solutions. The paper is motivated by the corresponding properties of the set of periodic solutions of ż = f(t, z) when f is periodic in t. Consideration of this complex equation gives information about the periodic solutions of the real equation ẋ = f(t, x).
Assemblages of the boat-shaped bivalve Odontogryphaea thirsae (Gabb, 1861) from southwestern Alabama are used to define three ontogenetic growth stages that are bounded by major discontinuities in either mineral structure or growth-line prominence. Features of the larval and juvenile stages are described here for the first time and are compared with the well-known morphologic features that distinguish adults (late dissoconchs).
The larval stage is represented by prodissoconch valves which are about 0.4 mm in height with suborbicular outlines, commarginal striations, and ridge-like, opisthogyral beaks. The juvenile (early dissoconch) stage is expressed by dissoconch valves up to 19 mm in height with elliptical outlines (height > length), indistinct commarginal growth lines, flat commissural planes, and tiny attachment areas on left valves; the valve interiors exhibit a posterior adductor muscle scar, a resilifer, and chomata. The adult (late dissoconch) stage is characterized by dissoconch valves >19 mm in height with subtriangular outlines, prominent commarginal growth lines, wavy commissural planes, and a keel-like terebratuloid fold.
Paleonvironmental and stratigraphic studies of the diversely fossiliferous Odontogryphaea thirsae beds indicate 0. thirsae (Gabb, 1861) thrived in a shallow, normal-marine, tropical sea that extended from Texas to Georgia about 57 million years ago.
To outline methods for deriving and validating intensive care unit (ICU) antimicrobial utilization (AU) measures from computerized data and to describe programming problems that emerged.
Retrospective evaluation of computerized pharmacy and administrative data.
ICUs from 4 academic medical centers over 36 months.
Investigators separately developed and validated programming code to report AU measures in selected ICUs. Use of antibacterial and antifungal drugs for systemic administration was categorized and expressed as antimicrobial-days (each day that each antimicrobial drug was given to each patient) and patient-days receiving antimicrobials (each day that any antimicrobial drug was given to each patient). Monthly rates were compiled and analyzed centrally, with ICU patient-days as the denominator. Results were validated against data collected from manual review of medical records. Frequent discussion among investigators aided identification and correction of programming problems.
AU data were successfully programmed though a reiterative process of computer code revision. After identifying and resolving major programming errors, comparison of computerized patient-level data with data collected by manual review of medical records revealed discrepancies in antimicrobial-days and patient-days receiving antimicrobials that ranged from less than 1% to 17.7%. The hospital from which numerator data were derived from electronic records of medication administration had the least discrepant results.
Computerized AU measures can be derived feasibly, but threats to validity must be sought out and corrected. The magnitude of discrepancies between computerized AU data and a gold standard based on manual review of medical records varies, with electronic records of medication administration providing maximal accuracy.
Measurements and theory are presented examining the relationship between mobility and doping in regioregular poly(3-hexylthiophene) (P3HT). Mobility is found to increase super-linearly with doping and is comparable to models reported for other conjugated polymers. Schottky measurements have been used to calculate the doping density and bulk mobility of regioregular P3HT. Aluminium Schottky contacts showed signs of native oxide disrupting current flow through the device. This effect was observed to degrade further with the introduction of dopant into the polymer. Titanium devices show a general shift of the Schottky characteristic to higher current levels with increased dopant. Field effect mobility of P3HT films was also calculated using thin-film transistor (TFT) structures. The field effect mobility values were observed to be more than two orders of magnitude higher than the bulk mobility value. The addition of dopant also increased gate leakage currents in TFT devices. The increased conductivity in doped polymer can increase off currents in the device; this is avoided by using Schottky contacts as the source and drain. Preliminary results on Schottky contact TFTs are also presented as well as a description of the operation of such a device.
Single crystals and epitaxial films of SiC - 4H and 6H were implanted at an energy of 40 and 90 KeV by ions of Al at various temperatures and high dose.
The implanted layers were studied before and after annealing by Raman scattering, Auger electron spectroscopy and SIMS. Results of this investigation show intensive graphitization of the implanted layer surface, the formation of great associations of defects in the implanted layer and shallow defects. It was found that recrystallization of the implanted layer pushes out a considerable part of aluminum atoms. The nature of the processes in silicon carbide during implantation and annealing is discussed.
We have investigated the effects of electron beam (EB) irradiation on the optical and electrical properties of GaAs/AlGaAs heterostructures in the energy range between 5 and 25 keV. By using 10 keV-EB irradiation, the photoluminescence from quantum wells is shown to be degraded at doses higher than 1×1019 electrons/cm2, further, the two-dimensional-electron-gas mobility is degraded at doses more than 5xl020 electrons/cm2. EB irradiation of 5 and 25 keV, on the other hand, produces no degradation of both properties even at these dose levels. Such an energy dependence of EB-induced damage can be interpreted in terms of the EB energy dependence of the electron penetration and energy-loss-rate. Electrons with an incident energy of 5 keV do not penetrate sufficiently deep into the active region, and 25 keV electrons have an energy-loss-rate that is too low to cause damage.