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Sexual dimorphism is common in many extant animals, but it is difficult to demonstrate in fossil species. Working with material from the Late Cretaceous of the U.S. Coastal Plain, we herein analyze sexual dimorphism in ostracodes from the superfamily Cytheroidea, a group whose extant members have males that are relatively more elongate than females. We digitized outlines of more than 6000 individual ostracode valves or carapaces, extracted size (area) and shape (length-to-height ratio) information, and used finite mixture models to assess hypotheses of sexual dimorphism. Male and female clusters can be discerned in nearly all populations with sufficient data, resulting in estimates of size and shape dimorphism for 142 populations across 106 species; an additional nine samples are interpreted to consist only of females. Dimorphism patterns varied across taxa, especially for body size: males range from 30% larger to 20% smaller than females. Magnitudes of sexual dimorphism are generally stable within species across time and space; we can demonstrate substantial evolutionary changes in dimorphism in only one species, Haplocytheridea renfroensis. Several lines of evidence indicate that patterns of sexual dimorphism in these ostracodes reflect male investment in reproduction, suggesting that this study system has the potential to capture variation in sexual selection through the fossil record.
Twenty-eight 14C analyses are reported for carbonized roots and other plant material collected from beneath 15 prehistoric lava flows erupted from the northeast rift zone (NERZ) of Mauna Loa Volcano (ML) utilizing the recovery techniques of Lockwood and Lipman (1980). Most samples were collected from the Hilo 7 1/2’ quadrangle during field work for a geologic map of that quadrangle (Buchanan-Banks, unpub data); a few sample sites are located in adjacent quadrangles: Piihonua to the west and Mountain View to the south. Altitudes are given in English units as well as metric to facilitate locating sites on USGS topographic maps.
Ninety-six new 14C dates are reported for carbonized roots and other plant material coll from beneath prehistoric lava flows and ash deposits from Mauna Loa (ML) and Kilauea volcanoes. Before 1976, only 10 flows from these volcanoes had been dated by radiocarbon methods. Collection of dateable material has been facilitated by an improved understanding of the conditions of charcoal formation and preservation beneath basaltic lavas (Lockwood & Lipman, 1979).
Radiocarbon is a useful tool for studying carbon dynamics in soil aggregates. The objective of the current study was to determine the mean residence time (MRT) of soil organic carbon (SOC) in macroaggregates and microaggregates under contrasting land uses. Contrasting land uses investigated at Alfisol (equivalent to Dermosol in Australian Soil Classification) sites were native pasture (NP), crop-pasture rotation (CP), and Eucalypt woodland (WL), whereas in Oxisol (Ferrosol in Australian Soil Classification) sites, land uses comprised improved pasture (IP), cropping (CR), and forest (FR). Soil aggregates were separated into macroaggregates (250–2000 μm) and microaggregates (53–250 μm) by wet-sieving, and their 14C signatures were determined by accelerator mass spectrometry (AMS). The 14C activity in both macro- and microaggregates was >100 pMC, indicating the presence of post-bomb carbon in the soil. The mean residence time (MRT) of SOC in macro- and microaggregates (MRTagg) was on average 68 yr longer in the Oxisol compared with that in the Alfisol. The MRTagg in microaggregates was 10 yr longer than that of macroaggregates in the Alfisol. However, the MRTagg in microaggregates was 50 yr shorter compared to macroaggregates in the Oxisol.
The MRT of macro- and microaggregates can be separated into active, slow, and stable SOC pools. Among the 3 SOC pools, the MRT of the stable pool is of higher significance in terms of SOC stabilization in soil aggregates because of its longer MRT. However, isolation and direct MRT estimation of the stable SOC pool is difficult. The MRT of active and slow SOC pools associated with macro- and microaggregates was measured using a SOC mineralization experiment to estimate the MRT of the stable SOC pool under contrasting land uses by applying a mass balance criterion. The MRT of active (MRTA) and slow (MRTS) SOC pools in macro- and microaggregates varied between 1–50 days and 13–38 yr, respectively. The estimated MRT of the stable pool carbon (MRTP) in microaggregates was 897 yr longer compared to that of macroaggregates in the Alfisol. However, in the Oxisol, MRTP in microaggregates was 568 yr shorter than that of macroaggregates. Among the land uses, WL in Alfisol and CR in Oxisol had longer MRTagg and MRTP compared to other land uses.
To assess the impact of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) mass spectrometry for rapid pathogen identification directly from early-positive blood cultures coupled with an antimicrobial stewardship program (ASP) in two community hospitals. Process measures and outcomes prior and after implementation of MALDI-TOF/ASP were evaluated.
Multicenter retrospective study.
Two community hospitals in a system setting, Houston Methodist (HM) Sugar Land Hospital (235 beds) or HM Willowbrook Hospital (241 beds).
Patients ≥18 years of age with culture-proven Gram-negative bacteremia.
Blood cultures from both hospitals were sent to and processed at our central microbiology laboratory. Clinical pharmacists at respective hospitals were notified of pathogen ID and susceptibility results.
We evaluated 572 patients for possible inclusion. After pre-defined exclusion criteria, 151 patients were included in the pre-intervention group and 242 were included in the intervention group. After MALDI-TOF/ASP implementation, the mean identification time after culture positivity was significantly reduced from 32 hours (±16 hours) to 6.5 hours (±5.4 hours) (P<.001); mean time to susceptibility results was significantly reduced from 48 (±22) hours to 23 (±14) hours (P<.001); and time to therapy adjustment was significantly reduced from 75 (±59) hours to 30 (±30) hours (P<.001). Mean hospital costs per patient were $3,411 less in the intervention group compared with the pre-intervention group ($18,645 vs $15,234; P=.04).
This study is the first to analyze the impact of MALDI-TOF coupled with an ASP in a community hospital setting. Time to results significantly differed with the use of MALDI-TOF, and time to appropriate therapy was significantly improved with the addition of ASP.
Infect. Control Hosp. Epidemiol. 2016;37(4):425–432
Children with conduct problems (CP) are a heterogeneous group. Those with high levels of callous–unemotional traits (CP/HCU) appear emotionally under-reactive at behavioural and neural levels whereas those with low levels of CU traits (CP/LCU) appear emotionally over-reactive, compared with typically developing (TD) controls. Investigating the degree to which these patterns of emotional reactivity are malleable may have important translational implications. Instructing participants with CP/HCU to focus on the eyes of fearful faces (i.e. the most salient feature) can ameliorate their fear-recognition deficits, but it is unknown whether this is mediated by amygdala response. It is also unknown whether focusing on fearful eyes is associated with increased amygdala reactivity in CP/LCU.
Functional magnetic resonance imaging (fMRI) was used to measure neural responses to fearful and calm faces in children with CP/HCU, CP/LCU and TD controls (n = 17 per group). On half of trials participants looked for a blue dot anywhere within target faces; on the other half, participants were directed to focus on the eye region.
Reaction time (RT) data showed that CP/LCU were selectively slowed in the fear/eyes condition. For the same condition, CP/LCU also showed increased amygdala and subgenual anterior cingulate cortex (sgACC)/orbitofrontal cortex (OFC) responses compared with TD controls. RT and amygdala response to fear/eyes were correlated in CP/LCU only. No effects of focusing on the eye region were observed in CP/HCU.
These data extend the evidence base suggesting that CU traits index meaningful heterogeneity in conduct problems. Focusing on regulating reactive emotional responses may be a fruitful strategy for children with CP/LCU.
Leprosy is a chronic disease predominantly affecting skin and nerves, which may result in deformity, disability and social stigma, creating problems for patients and their families. Africa is the third most affected region world-wide after Asia and South America (WHO, 2009). In 2009, eight African countries still reported more than one new leprosy case per 10 000 population.
In many countries leprosy work is being integrated into general health services, so all medical professionals need to be aware of the symptoms and signs of leprosy. Since new patients may have nerve function impairment at diagnosis, every health professional should know how to assess and manage nerve impairment caused by leprosy (Rijk et al., 1994).
Leprosy is caused by Mycobacterium leprae, an acid-fast intracellular organism not yet cultivated in vitro. The organism was first identified in the nodules of lepromatous leprosy patients by Hansen in 1873. M. leprae parasitizes skin macrophages and peripheral nerve Schwann cells.
M. leprae can be grown in the mouse footpad, but growth is slow. The nine-banded armadillo is susceptible to M. leprae infection, and develops disease with widespread bacterial multiplication. The armadillo and mouse models of M. leprae infection have been useful for producing M. leprae for biological studies and studying drug sensitivity patterns.
A study of the interface chemical and physical abruptness of Si-Ge heterostructures grown on (001) Si by molecular beam epitaxy under atomic hydrogen exposure is reported. Atomic hydrogen (AH) was produced by the dissociation of molecular hydrogen interacting with a hot tungsten filament. Secondary-ion mass spectroscopy (SIMS) of structures made of alternating Ge (0.5 nm)/Si (40 nm) layers demonstrated that AH can effectively suppress Ge surface segregation. The segregation length was reduced from 1.5 nm to about 0.5 nm in films grown at a hydrogen partial pressure of −5 × 10-3 Pa and cell temperature of 2140 °C with an estimated cracking efficiency of ~5%. However, the high hydrogen background pressure had detrimental effects on the physical sharpness of the interfaces. This was evidenced by comparing the interface quality of Si/Ge atomic layer superlattices grown with and without AH exposure. X-ray reflectivity and Raman spectroscopy revealed a significant increase of the interface roughness, although the periodic character and the good crystallinity of the structures were preserved.
There are few easily identifiable or accessible sources where the results of international irrigation research have been brought together and interpreted in coherent and useful ways for individual crops. This is in part due to the diversity of sources, and also to the difficulty of reconciling the results of research conducted in contrasting situations, often with insufficient supporting information, to allow the results to be extrapolated to new situations with confidence (Carr, 2000a).
A scientific understanding of the role that water plays in the growth and development of crops is essential, but this knowledge needs to be interpreted and presented as practical advice in a language that can assist planners, irrigation engineers, irrigation agronomists and producers to allocate and use water, whether rainfall or irrigation, effectively and profitably. Communication between the professions attempting to improve irrigation water management for the benefit of the commercial producer and the wider community can always be improved. Field experiments must be designed and managed to quantify with precision the (marketable) yield responses of crops to water. Adequate supporting measurements need to be taken to enable the results to be interpreted and applied with confidence to other locations, or at other times, where the climate, weather and/or soils may be different. Site specific, single discipline, empirical studies should normally be avoided. But, to minimise duplication of effort, existing information on the water relations and irrigation need of individual crops first needs to be collated and interpreted in practically useful ways. This is especially true for plantation crops having international commercial importance (Carr, 2000a).
Sugar cane (Saccharum officinarum L., the so-called Noble Cane because of its fine thick stem) is believed to have originated in the islands of the South Pacific, probably New Guinea (2–10° S) having evolved through human selection from strains of two wild species S. robustum and S. spontaneum and hybridisation with S. sinense (Purseglove, 1972; Bull and Glasziou, 1976; Julien et al., 1989; Jones et al., 1990; Simmonds, 1998). Because of its natural sweetness, it has been grown for chewing since ancient times in the Pacific and South-east Asia. The production of sugar from sugar cane began in India, followed by China, Persia (Iran), Egypt and Spain and elsewhere around the Mediterranean. In the seventeenth century the first plantations were established in the West Indies, and the resultant need for labour, particularly for harvesting, led to sugar cane's links with the slave trade.
Most of the commerce between Europe and the sugar regions of the west that followed was subsequently based on the outward shipment of slaves and the homeward carriage of sugar, molasses and rum (Purseglove, 1972; Hobhouse, 1985). Molasses, the dark brown viscous liquid residue left behind after the centrifugal process has ended and no more sucrose can be extracted, is one of the most important by-products (contains 50% fermentable sugars) from the manufacture of cane sugar. It is used as a raw material in industry. Rum is produced by the fermentation of molasses, followed by distillation. Other products include industrial ethyl alcohol (ethanol), which is manufactured from molasses, and bagasse, the fibrous residue left after the extraction of juice from the cane (used for fuel in the sugar factory, as well as in various manufacturing processes). The pith from the bagasse is used as a stockfeed. Not much of the plant is wasted.
The centre of diversity of the cocoa tree (Theobroma cacao L.) is believed to be within the rainforests of lowland northern South America where the greatest range of variation in natural populations exists (Cheesman, 1944; Simmonds, 1998). The plant is grown for its fruits known as cocoa pods (botanically indehiscent drupes). The pods contain seeds, which are fermented with the mucilage surrounding them and then dried to give fermented dried cocoa, the raw material used in the food industry for the production of chocolate and powder (for drinking, baking and ice cream manufacture). A small proportion is also sold as cocoa butter, which is used in the pharmaceutical and cosmetic industries (Wood, 1985a).
In its natural habitat cocoa is a small tree in the lower storey of the evergreen rainforest. Cocoa has been cultivated since ancient times (at least 2000 years) in Central America, from Mexico to southern Costa Rica. After the arrival of the Spaniards in the sixteenth century, cocoa spread rapidly in the New World. It was introduced into South-east Asia in the seventeenth century and to West Africa in the nineteenth century. By 2008, the total planted area of cocoa in the world was estimated to be about 8.6 million ha, of which 67% is in West Africa and only 17% in the Americas and the Caribbean. It is nearly all grown within 20° N and 20° S of the equator (World Cocoa Foundation, 2010). The largest individual producer is Côte d'Ivoire (1.22 million tonnes; 2.3 million ha in 2008), followed by Ghana (662 000 t; 1.75 million ha), Indonesia (490 000 t; 990 000 ha), Nigeria (250 000 t; 1.15 million ha), Cameroon (227 000 t; 500 000 ha) and Brazil (157 000 t; 641 000 ha) (areas harvested from FAO, 2010a: production from ICCO, 2010). West Africa now produces 69% of the world's annual total of 3.6 million tonnes of cocoa. The market value of the cocoa crop is US$5.1 billion (World Cocoa Foundation, 2010).
The sisal plant (Agave sisalana Perrine) is a source of coarse leaf fibres. These are used by industry in the manufacture of twines and ropes, carpet-backing, bags and matting (Figure 8.1). The principal areas of production are Brazil, where it is predominantly a smallholder crop, and East Africa, where it is a large-scale plantation crop (Figure 8.2). The importance of the crop, which is adapted to dry areas, has declined since the mid 1960s due mainly to competition from synthetics made from oil-based polypropylenes. As a result, little has changed in production methods in the last 50 years, and resources for research have been limited (Shamte, 2001).
Sisal belongs to a botanically complex group of American plants, the Agavaceae. It differs from many other plantation crops (except pineapple) in that it has a photosynthetic adaptation (crassulacean acid metabolism, CAM) that facilitates the uptake of carbon dioxide at night. This dramatically improves its water-use efficiency when it is grown under dry conditions.