1,041 research outputs found
TWO DIFFERENT TYPES OF PHOTOCHEMISTRY IN PHYCOERYTHROCYANIN α-SUBUNIT
The photochemical activities of phycoerythrocyanin α-subunits from Mastigocladus laminosus separated by isoelectric focusing were tested by irradiating at 500, 550, 577 and 600 nm. Two types of photoreversible photochromic responses have been characterized by absorption and absorption difference spectroscopy. Type I is the well-known absorption shift from 571 to 506 nm. Type II is a new response characterized by a line-broadening of the 570 nm absorption
Unbound states of 32Cl and the 31S(p,\gamma)32Cl reaction rate
The 31S(p,\gamma)32Cl reaction is expected to provide the dominant break-out
path from the SiP cycle in novae and is important for understanding enrichments
of sulfur observed in some nova ejecta. We studied the 32S(3He,t)32Cl
charge-exchange reaction to determine properties of proton-unbound levels in
32Cl that have previously contributed significant uncertainties to the
31S(p,\gamma)32Cl reaction rate. Measured triton magnetic rigidities were used
to determine excitation energies in 32Cl. Proton-branching ratios were obtained
by detecting decay protons from unbound 32Cl states in coincidence with
tritons. An improved 31S(p,\gamma)32Cl reaction rate was calculated including
robust statistical and systematic uncertainties
Rates for the reactions antiproton-proton --> pi phi and gamma phi
We study antiproton-proton annihilation at rest into and
. Rescattering by and
for states is sizable, of
order in the branching ratio, but
smaller than experiment. For the
rescattering contributions are negligible, but the channel is well
explained by a intermediate state combined with vector meson
dominance.Comment: 12 pages, plain latex, 2 postscript figures available upon request,
PSI-PR-93-2
Multielectron spectroscopy: Auger decays of the argon 2p hole
All the different Auger decay paths of Argon 2p holes have been characterized using a time of flight spectrometer of the magnetic bottle type. All electrons (the photoelectron and up to three Auger electrons) are detected in coincidence and resolved in energy. Double Auger decay is shown to proceed either through a direct process or by intense cascade paths, implying highly excited autoionizing Ar2+ states, which are identified as Ar2+ 3sâ2 correlation satellites. Triple Auger decay is also observed and estimated to account for 0.2% only of all Auger decay
Dynamics of electron emission in double photoionization processes near the Krypton 3d threshold
Two electron emission following photoabsorption near the Kr 3d threshold is investigated both experimentally and theoretically. On the experimental side, electron/electron coincidences using a magnetic bottle time of flight spectrometer allow us to observe the complete Double Photo Ionisation (DPI) continua of selected Kr2+ final states, and to see how these continua are affected by resonant processes in the vicinity of the Kr 3d threshold. The analysis is based on a quantum mechanical approach that takes into account the contribution of three different processes: A) Auger decay of the inner 3d vacancy with the associated post collision interaction (PCI) effects, B) capture of slow photoelectrons into discrete states followed by valence multiplet decay (VMD) of the excited ionic states and C) valence shell DPI. The dominant process for each Kr2+(4p-2) final state is the photoionization of the inner shell followed by Auger decay of the 3d vacancies. Moreover, for the 4p2(3P) and 4p-2(1D) final ionic states an important contribution comes from the processes of slow photoelectron capture followed by VMD as well as from double ionization of the outer shell involving also VMD
Arctic seabirds and shrinking sea ice: egg analyses reveal the importance of ice-derived resources
In the Arctic, sea-ice plays a central role in the functioning of marine food webs and its rapid shrinking has large effects on the biota. It is thus crucial to assess the importance of sea-ice and ice-derived resources to Arctic marine species. Here, we used a multi-biomarker approach combining Highly Branched Isoprenoids (HBIs) with ÎŽ13C and ÎŽ15N to evaluate how much Arctic seabirds rely on sea-ice derived resources during the pre-laying period, and if changes in sea-ice extent and duration affect their investment in reproduction. Eg
Rescue bedside laparotomy in the intensive care unit in patients too unstable for transport to the operating room
INTRODUCTION: The prognoses of critically ill patients with a requirement for emergency laparotomy and severe respiratory and/or hemodynamic instability precluding transport to the operating room (OR) are often fatal without surgery. Attempting emergency surgery at the bedside might equally result in an adverse outcome. However, risk factors and predictors that could support clinical decision making have not been identified so far. This study describes the clinical characteristics, indicative pathophysiology and outcomes in patients undergoing resuscitative laparotomy in the intensive care unit (ICU). METHODS: This was a retrospective observational study of all critically ill adult patients undergoing resuscitative laparotomy in the ICUs of a German university hospital from January 2005 to July 2013. Clinical characteristics, risk factors, and treatments were compared between survivors and non-survivors. The primary endpoint was 28-day survival. RESULTS: A total of 41 patients with a median age of 64 (21 to 83) were included. The most frequent reasons for ICU admission were sepsis, pneumonia, and pancreatic surgery. All patients were mechanically ventilated, receiving vasopressors, and were in multiple organ failure. Twenty-nine patients (70.7%) were on renal replacement therapy and two patients (4.9%) on extracorporeal membrane oxygenation. The main reasons for surgery were suspected intra-abdominal bleeding (39.0%), suspected intestinal ischemia (24.4%) or abdominal compartment syndrome (24.4%). Twenty-eight-day, ICU and hospital mortalities were 75.6%, 80.5%, and 82.9%, respectively. In six out of ten patients (60%) who survived surgery for more than 28âdays, bedside laparotomy was rated as a life-saving procedure by an interdisciplinary group of the investigators. CONCLUSIONS: These findings suggest that in selected critically ill patients with a vital indication for emergency laparotomy and severe cardiopulmonary instability precluding transport to the OR, a bedside resuscitative laparotomy in the ICU can be considered as a rescue procedure, even though very high mortality is to be expected
Solid-fluid mixing behavior of conical spouted beds with internal devices
The effect of draft tubes and fountain confiner on the gas and solids mixing behavior is studied in conical
spouted beds. Accordingly, the bed porosity has been determined in different hydrodynamic regimes of
1:1; 1:25 and 1:5 u=ums , with beds equipped with draft tubes of 0%; 56% and 100% opening ratio. These
devices significantly affect the gas residence time and particle cycle time distributions, which are further
improved by using a fountain confiner, specially when high inlet gas flow rates are desired. The addition
of this device was found to remove stagnant gas pockets over the annular zone, while reducing the par-
ticle cycle time by 15% with the OSDT configuration at 1:5 u=u ms . This reduction heavily depends on the
distance between the bed surface and the fountain confiner. By including draft tubes, the expected par-
ticle cycle time can be more than doubled due to the reduced annular-spot solids circulation. Therefore, it
was found that a combination of internal devices and operating flow rate present a promising strategy to
control the gas flow pattern, while keeping the distribution of particles cycle times required for each
application.This work has been carried out with the financial support from
the Spainâs Ministries of Economy and Competitiveness (CTQ2016-
75535-RĂ°AEI=FEDER; UEĂ) and Science and Innovation
(PDI2019-107357RB-I00Ă°AEI=FEDER; UEĂ), the Basque Government
(IT218-19) and the University of the Basque Country UPV/EHU (US16/21). Aitor Atxutegi is grateful for his Ph.D. grant from the
University of the Basque Country UPV/EHU(PFI15-2017)
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Community financing in entrepreneurship: a focus on women entrepreneurs in the developing world
Studies on the impact of groupâbased financing on women entrepreneurs in the developing world are underrepresented in entrepreneurship research. With this exploratory study, we focus on women entrepreneurship from a community financing perspective to account for the underlying mechanisms of a community financing scheme and its impact on women entrepreneurs in the developing world. Data generated by interviewing 75 women entrepreneurs in Nigeriaâs gendered financial markets revealed that âAjoâ,âa community financing scheme shaped their entrepreneurial journeys, including their social structures. In their context, an overlay of prosocial acts of reciprocity, solidarity, collectivism, camaraderie, and trust underpinned how they pooled and shared financial resources. These findings contribute to our understanding of how women entrepreneurs engaged and interacted with a community financing scheme in their endeavours to promote their businesses in financial markets where gender biases existed. Such an understanding holds academic, policy, and social implications
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