1,466 research outputs found
Soil-transmitted helminth infections
More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections
Growth Mechanism of Helicoidal Nickel Whiskers
NICKEL whiskers obtained by reduction of the
iodide of the metal can be classified into two
categories :
(i) rectilinear whiskers
(ii) helicoidal whiskers
In general, these whiskers are formed by a stacking
of small idiomorphic crystals. The law governing such
stackings was determined theoretically in a previous
investigation .1,2 It was shown that they were formed
from nickel iodide in fusion and that the theory of
dendritic growth was quite true for rectilinear
whiskers ; the axes of growth are of low indices
( , ---100> ) and the conditions required for
dendritic growth as described by Papapetrou3 are
fulfilled.
Rectilinear whiskers without branches are obtained,
because one of the directions of dendritic growth is
favoured and the development takes place only in that
direction.
This paper presents a study of the growth mechanisms
of helicoidal whiskers
Growth Mechanism of Helicoidal Nickel Whiskers
Nickel whiskers obtained by reduction of the iodide of the metal can be classified into two categories:-
- Rectilinear whiskers
- Spiral whiskers
Rectilinear whiskers without branches are obtained because one of the directions of dendritic growth is favoured and the development takes place only in that direction
Intercalibration of the Hb3gr 40Ar/39Ar dating standard.
The 40Ar/39Ar dating technique is based on the knowledge of the age of neutron fluence monitors (standards). Recent investigations have improved the accuracy and precision of the ages of most of the Phanerozoic-aged standards (e.g. Fish Canyon Tuff sanidine (FCs), Alder Creek sanidine, GA1550 biotite and LP-6 biotite); however, no specific study has been undertaken on the older standards (i.e. Hb3gr hornblende and NL-25 hornblende) generally used to date Precambrian, high Ca/K, and/or meteoritic rocks.In this study, we show that Hb3gr hornblende is relatively homogenous in age, composition (Ca/K) and atmospheric contamination at the single grain level. The mean standard deviation of the 40Ar/39ArK (F-value) derived from this study is 0.49%, comparable to the most homogeneous standards. The intercalibration factor (which allows direct comparison between standards) between Hb3gr and FCs is RFCsHb3gr = 51.945 0.167. Using an age of 28.02 Ma for FCs, the age of Hb3gr derived from the R-value is 1073.6 5.3 Ma (1σ, internal error only) and 8.8 Ma (including all sources of error). This age is indistinguishable within uncertainty from the K/Ar age previously reported at 1072 11 Ma [Turner G., Huneke, J.C., Podosek, F.A., Wasserburg, G.J., 1971. 40Ar-39Ar ages and cosmic ray exposure ages of Apollo 14 samples. Earth Planet. Sci. Lett. 12, 19-35]. The R-value determined in this study can also be used to intercalibrate FCs if we consider the K/Ar date of 1072 Ma as a reference age for Hb3gr. We derive an age of 27.95 0.19 Ma (1σ, internal error only) for FCs which is in agreement with the previous determinations. Altogether, this shows that Hb3gr is a suitable standard for 40Ar/39Ar geochronology
Equal Protection and Aesthetic Zoning: A Possible Crack and a Preemptive Repair
In Village of Willowbrook v. Olech, the property owner alleged the Village intentionally demanded a 33-foot easement as a condition of connecting her property to the municipal water supply where the Village required only a 15-foot easement from other similarly situated property owners. The complaint further described the village\u27s demand as irrational and wholly arbitrary. According to the Seventh Circuit, the property owner could allege an equal protection violation by asserting the state\u27s action was motivated solely by a spiteful effort to \u27get\u27 him for reasons wholly unrelated to any legitimate state objective. On appeal, the Supreme Court agreed, holding that [t]hese allegations, quite apart from the Village\u27s subjective motivation, are sufficient to state a claim for relief under traditional equal protection analysis. Although it affirmed the Seventh Circuit\u27s decision, the Court explicitly [did] not reach the alternative theory of \u27subjective ill will\u27 relied on by [the lower] court.
This article considers whether Olech infers that unreasoned zoning decisions violate the Equal Protection Clause, and explores the meaning of similarly situated. The authors further examine what type of evidence might be necessary to ensure that aesthetic regulations pass constitutional muster with respect to the Fourteenth Amendment\u27s Equal Protection Clause
Longitudinal and Transverse Response Functions in ^(56)Fe(e,e') at Momentum Transfer near 1 GeV/c
Inclusive electron-scattering cross sections have been measured for ^(56)Fe in the quasielastic region at electron energies between 0.9 and 4.3 GeV, at scattering angles of 15° and 85°. Longitudinal and transverse response functions at a q of 1.14 GeV/c have been extracted using a Rosenbluth separation. The experimental Coulomb sum has been obtained with aid of an extrapolation. The longitudinal response function, after correction for Coulomb distortion, is lower than quasifree-scattering-model predictions at the quasielastic peak and on the high-ω side
Stabilization and control system power sensitivity study
Stabilization and control system sensitivity to power-off failure rate studied by simulated missions using block power switchin
Mechanical mode dependence of bolometric back-action in an AFM microlever
Two back action (BA) processes generated by an optical cavity based detection
device can deeply transform the dynamical behavior of an AFM microlever: the
photothermal force or the radiation pressure. Whereas noise damping or
amplifying depends on optical cavity response for radiation pressure BA, we
present experimental results carried out under vacuum and at room temperature
on the photothermal BA process which appears to be more complex. We show for
the first time that it can simultaneously act on two vibration modes in
opposite direction: noise on one mode is amplified whereas it is damped on
another mode. Basic modeling of photothermal BA shows that dynamical effect on
mechanical mode is laser spot position dependent with respect to mode shape.
This analysis accounts for opposite behaviors of different modes as observed
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