Interaction Between Animals, Vegetation, and Fire in Southern Rhodesia

Author Institution: University College of Rhodesia and Nyasaland, Salisbury, Southern Rhodesi

The interactions of the soil micro-organisms

(1) A record of numbers of soil fungi, and bacteria and actinomycetes, in a fallow plot in the Royal Botanic Garden, Edinburgh, was kept over the course of one year, 1937 -1938, together with variations in soil moisture, soil temperature, soil pH, and soil organic matter content.(2) The numbers of soil fungi exhibited a marked seasonal periodicity with a biennial maximum in April and October.(3) The numbers of soil bacteria and actinomycetes exhibited similar fluctuations, but with maximums in May and September.(4) Records of numbers of certain individual species were also taken. Fluctuations in numbers of one or two of the species departed considerably from the mean as indicated by the fluctuations in total numbers of soil fungi.(5) Numbers of fungi developing on agar plates exposed to the air over the soil plot were recorded over the year.(6) The effect of four different soil treatments on soil fungi was investigated. Sterilised dung, nutrient solution, and weak growth caused a significant depression in numbers after 3 months. Sterilised filter -paper had no effect.(7) A new method of distinguishing between fungal spores and fungal mycelium is outlined

Template-Assisted Hydrothermal Growth of Aligned Zinc Oxide Nanowires for Piezoelectric Energy Harvesting Applications.

A flexible and robust piezoelectric nanogenerator (NG) based on a polymer-ceramic nanocomposite structure has been successfully fabricated via a cost-effective and scalable template-assisted hydrothermal synthesis method. Vertically aligned arrays of dense and uniform zinc oxide (ZnO) nanowires (NWs) with high aspect ratio (diameter ∼250 nm, length ∼12 μm) were grown within nanoporous polycarbonate (PC) templates. The energy conversion efficiency was found to be ∼4.2%, which is comparable to previously reported values for ZnO NWs. The resulting NG is found to have excellent fatigue performance, being relatively immune to detrimental environmental factors and mechanical failure, as the constituent ZnO NWs remain embedded and protected inside the polymer matrix.The authors thank Yeonsik Choi for discussions and experimental support. S.K.-N., C.O., and A.D. are grateful for financial support from the European Research Council through an ERC Starting Grant (Grant no. ERC-2014-STG-639526, NANOGEN). F.L.B. and R.A.W. thank the EPSRC Cambridge NanoDTC, EP/G037221/1, for studentship funding. P.S.J. acknowledges the support of TEP-1900 and Talentia Postdoc Program, cofunded by the European Union’s Seventh Framework Program, Marie Skłodowska-Curie actions (COFUND Grant Agreement 267226) and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía. S-L.S acknowledges support through the EPSRC grant EP/M010589/1This is the final version of the article. It first appeared from American Chemical Society via http://dx.doi.org/10.1021/acsami.6b04041

Highly sensitive piezotronic pressure sensors based on undoped GaAs nanowire ensembles

Semiconducting piezoelectric materials have attracted considerable interest due to their central role in the emerging field of piezotronics, where the development of a piezo-potential in response to stress or strain can be used to tune the band structure of the semiconductor, and hence its electronic properties. This coupling between piezoelectricity and semiconducting properties can be readily exploited for force or pressure sensing using nanowires, where the geometry and unclamped nature of nanowires render them particularly sensitive to small forces. At the same time, piezoelectricity is known to manifest more strongly in nanowires of certain semiconductors. Here, we report the design and fabrication of highly sensitive piezotronic pressure sensors based on GaAs nanowire ensemble sandwiched between two electrodes in a back-to-back diode configuration. We analyse the current-voltage characteristics of these nanowire-based devices in response to mechanical loading in light of the corresponding changes to the device band structure. We observe a high piezotronic sensitivity to pressure, of ~7800 meV/MPa. We attribute this high sensitivity to the nanowires being fully depleted due to the lack of doping, as well as due to geometrical pressure focusing and current funneling through polar interfaces

Impact of race, ethnicity, and BMI on achievement of pathologic complete response following neoadjuvant chemotherapy for breast cancer: a pooled analysis of four prospective Alliance clinical trials (A151426)

Previous studies demonstrated poor response to neoadjuvant systemic therapy (NST) for breast cancer among black women and women who are overweight or obese but this may be due to chemotherapy under dosing. We assessed associations of race, ethnicity and body mass index (BMI) with pathologic complete response (pCR) in clinical trial populations

A triboelectric generator based on self-poled Nylon-11 nanowires fabricated by gas-flow assisted template wetting

Triboelectric generators have emerged as potential candidates for mechanical energy harvesting, relying on motion-generated surface charge transfer between materials with different electron affinities. In this regard, synthetic organic materials with strong electron-donating tendencies are far less common than their electron-accepting counterparts. Nylons are notable exceptions, with odd-numbered Nylons such as Nylon-11, exhibiting electric polarisation that could further enhance the surface charge density crucial to triboelectric generator performance. However, the fabrication of Nylon-11 in the required polarised δ′-phase typically requires extremely rapid crystallisation, such as melt-quenching, as well as “poling” via mechanical stretching and/or large electric fields for dipolar alignment. Here, we propose an alternative one-step, near room-temperature fabrication method, namely gas-flow assisted nano-template (GANT) infiltration, by which highly crystalline “self-poled” δ′-phase Nylon-11 nanowires are grown from solution within nanoporous anodised aluminium oxide (AAO) templates. Our gas-flow assisted method allows for controlled crystallisation of the δ′-phase of Nylon-11 through rapid solvent evaporation and an artificially generated extreme temperature gradient within the nanopores of the AAO template, as accurately predicted by finite-element simulations. Furthermore, preferential crystal orientation originating from template-induced nano-confinement effects leads to self-poled δ′-phase Nylon-11 nanowires with higher surface charge distribution than melt-quenched Nylon-11 films, as observed by Kelvin probe force microscopy (KPFM). Correspondingly, a triboelectric nanogenerator (TENG) device based on as-grown templated Nylon-11 nanowires fabricated via GANT infiltration showed a ten-fold increase in output power density as compared to an aluminium-based triboelectric generator, when subjected to identical mechanical excitations.This work was financially supported by a grant from the European Research Council through an ERC Starting Grant (Grant no. ERC-2014-STG-639526, NANOGEN). S. K.-N., Y. S. C. and A. D. are grateful for financial support from this same grant. Y. S. C. is grateful for studentship funding through the Cambridge Commonwealth, European & International Trust. Q. J. is grateful for financial support through a Marie Sklodowska Curie Fellowship, H2020-MSCAIF-2015-702868. CB thanks the EPSRC Cambridge NanoDTC, EP/G037221/1, for studentship funding

Illness Perception Mediates the Relationship Between the Severity of Symptoms and Perceived Health Status in Patients With Behçet Disease

Objective: The aim of this study was to investigate the relationship between psychological representations of illness, perceived health status, and self-assessment of symptom severity in patients with Behçet disease, a rare long-term incurable condition with unclear etiology. Methods: Using cross-sectional survey design, data on self-administered questionnaires on illness perception, health status, symptoms severity, and demographic characteristics were collected from 273 patients with Behçet disease (age range, 18–65 years). The data were subjected to mediation analysis to test whether cognitive and emotional components of illness perception mediate the relationship between the severity of symptoms and heath status. Results: The results support our hypotheses that cognitive components of illness perception (perceived consequences and identity of the illness) mediate the link between symptom activity and pain, whereas emotional components of the illness (emotional representations about the illness) mediate the relationship between disease activity and perceived energy level. Conclusions: The robustness of these mediation effects suggests potential directions for clinical psychologists and health care practitioners in developing support programs. We supplement our study with Open Access database containing information about type ofmedication, comorbidmood disorder, and detailed measurement of the severity of BD symptoms for sharing and accumulating multidisciplinary knowledge aiming to support the development of interventions. Addressing psychological aspects of BD will help to manage complex patients effectively

A double blind randomized trial of wound infiltration with ropivacaine after breast cancer surgery with axillary nodes dissection

<p>Abstract</p> <p>Background</p> <p>The effect of local infiltration after breast surgery is controversial. This prospective double blind randomized study sought to document the analgesic effect of local anaesthetic infiltration after breast cancer surgery.</p> <p>Methods</p> <p>Patients scheduled for mastectomy or tumorectomy and axillary nodes dissection had immediate postoperative infiltration of the surgical wound with 20 ml of ropivacaine 7.5 mg.ml^-1or isotonic saline. Pain was assessed on a visual analogue scale at H2, H4, H6, H12, H24, H72, and at 2 month, at rest and on mobilization of the arm. Patient'comfort was evaluated with numerical 0-3 scales for fatigue, quality of sleep, state of mood, social function and activity.</p> <p>Results</p> <p>Twenty-two and 24 patients were included in the ropivacaine and saline groups respectively. Postoperative pain was lower at rest and on mobilization at 2, 4 and 6 hour after surgery in the ropivacaine group. No other difference in pain intensity and patient 'comfort scoring was documented during the first 3 postoperative days. Patients did not differ at 2 month for pain and comfort scores.</p> <p>Conclusion</p> <p>Single shot infiltration with ropivacaine transiently improves postoperative pain control after breast cancer surgery.</p> <p>Trial registration number</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01404377">NCT01404377</a></p

Does shear wave ultrasound independently predict axillary lymph node metastasis in women with invasive breast cancer?

Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer(®) ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness <50 kPa to 41 % for tumours with a mean stiffness of >150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging