4,141 research outputs found
Enforcing Arizona's SB 1070: A State of Confusion
No full textArizona and the federal government await a decision from a Phoenix district judge on whether enforcement of SB 1070 will move forward on July 29th, or whether all or some parts of the law will be enjoined. Meanwhile, local law enforcement is struggling to interpret SB 1070 and provide training to officers, which could be further complicated if the judge allows only some parts of the law to go forward. In a new report released today by the Immigration Policy Center, Enforcing Arizona's SB 1070: A State of Confusion (below), journalist Jeffrey Kaye reveals that "instead of 'statewide and uniform practices' as directed by the governor, Arizona police agencies have developed a patchwork of guidelines based on varying interpretations of the law." Kaye's reporting includes interviews with police officials, who cite concerns with implementing the new law, and a review of training materials that suggest the implementation of SB 1070 will differ from one jurisdiction to another, and even within police agencies, and "will be burdensome, costly, and distort priorities.
Predictive Association of Pre-Operative Defect Areas in the Outer Retinal Layers With Visual Acuity in Macular Hole Surgery
No full textPurpose: The purpose of this study was to develop methods to model the external limiting membrane (ELM) and ellipsoid zone (EZ) within the elevated cuff surrounding a macular hole (MH) to determine if the predicted size of the defect in these layers after virtual flattening was associated with the actual postoperative defect and best corrected visual acuity (BCVA). Methods: Patients were included who had undergone successful MH surgery. The defects in the ELM and EZ after virtual flattening were modeled using in-house software. Main outcomes were postoperative defects in ELM and EZ at 2 months and BCVA at 12 months. Results: Fifty-eight patients were included. BCVA improved from 0.87 (0.31) logMAR pre-operatively to 0.26 (0.21) at 12 months (P < 0.001). For both the ELM and EZ, the predicted virtually flattened pre-operative defects were associated with the actual postoperative defects at 2 months (R-2 = 0.33, P < 0.01 and R-2 = 0.50, P < 0.01, respectively). There was a significant association of BCVA at 12 months (adjusted R-2 = 0.85) with the pre-operative modeled area of the defect in the ELM (P < 0.01) and to a lesser extent with the defect in the EZ (P < 0.01) and base of the MH (P < 0.01). Conclusions: Virtually flattening of the pre-operative defect in the ELM provides important predictive information of visual acuity. Incorporation of tools into commercially available optical coherence tomography (OCT) devices to facilitate such measurements would provide the clinician with important prognostic information. Translational Relevance: We have developed methodology that can potentially be used to predict the postoperative state of the outer retinal layers and the associated visual outcome in patients undergoing surgery for MH
Letter Regarding: Establishing a Biomarker for the Prediction of Short-Term Graft Detachment After Descemet Membrane Endothelial Keratoplasty
No full textRisk factors for corneal epithelial wound healing: Can sex play a role?
No full textPurpose To determine if sex is associated with corneal epithelial wound healing time in patients with persistent corneal epithelial defects (PCEDs). Methods Retrospective case series on patients with PCED from November 2014 to January 2019. Records of 127 patients with diagnosis of PCED were reviewed. Patients with an epithelial defect that lasted more than two weeks in the absence of an active corneal infection were included. Main outcome was corneal epithelial wound healing time. Results 55 patients (29 males) with a mean age of 65.3 +/- 16.5 years were included. No difference was found between female and male patients in terms of risk factors, age, treatment strategies or intervals between visits (median of 15 days in females and 12 days in males; p = 0.24). Median duration of the PCED was 51 days (IQR 32-130), with a median number of 5 clinical visits (IQR 4-8). Female patients had significantly longer healing times (p = 0.004) and a corresponding increase in the number of clinical visits (median of 7 visits vs. 5 clinical visits in males, p = 0.012). Conclusion Results from this study suggest female patients with PCED might have a longer corneal epithelial wound healing duration and may therefore require earlier intervention
Selective-Area MOCVD Growth and Carrier-Transport-Type Control of InAs(Sb)/GaSb Core-Shell Nanowires
No full textWe
report the first selective-area growth of high quality InAs(Sb)/GaSb
core–shell nanowires on Si substrates using metal–organic
chemical vapor deposition (MOCVD) without foreign catalysts. Transmission
electron microscopy (TEM) analysis reveals that the overgrowth of
the GaSb shell is highly uniform and coherent with the InAs(Sb) core
without any misfit dislocations. To control the structural properties
and reduce the planar defect density in the self-catalyzed InAs core
nanowires, a trace amount of Sb was introduced during their growth.
As the Sb content increases from 0 to 9.4%, the crystal structure
of the nanowires changes from a mixed wurtzite (WZ)/zinc-blende (ZB)
structure to a perfect ZB phase. Electrical measurements reveal that
both the n-type InAsSb core and p-type GaSb shell can work as active
carrier transport channels, and the transport type of core–shell
nanowires can be tuned by the GaSb shell thickness and back-gate voltage.
This study furthers our understanding of the Sb-induced crystal-phase
control of nanowires. Furthermore, the high quality InAs(Sb)/GaSb
core–shell nanowire arrays obtained here pave the foundation
for the fabrication of the vertical nanowire-based devices on a large
scale and for the study of fundamental quantum physics
Origin of the low thermal conductivity of the thermoelectric material beta-Zn(4)Sb(3): An ab initio theoretical study
No full textBy modeling beta-Zn(4)Sb(3) material as a Zn(36)Sb(30) crystal with defects, the crystal structure and thermal properties of beta-Zn(4)Sb(3) are studied by ab initio method to explain its extremely low thermal conductivity at moderate temperature. The formation and migration energies of defects are calculated and used to explain the partial occupation of Zn at the lattice sites, the disordered local structures and the origin of the low thermal conductivity of beta-Zn(4)Sb(3). Our study also unravels the puzzling dependence of thermal conductivity on doping in beta-Zn(4)Sb(3). A doping strategy is proposed to improve the thermoelectric performance of beta-Zn(4)Sb(3). (C) 2011 American Institute of Physics. [doi:10.1063/1.3599483
Eye Banking: One Cornea for Multiple Recipients
No full textPurpose: Corneal transplantation is the most frequently performed transplant procedure. In much of the world, the demand for donor tissue heavily outstrips supply. With developments within lamellar corneal graft surgery, the use of split corneal donor tissue to increase donor tissue supply seems a pragmatic solution to reduce the supply and demand mismatch. This is especially important with tissue supply expected to be affected by the COVID-19 pandemic. Methods: A literature review of techniques was performed, enabling multiple transplants to be derived from a single donor and simulation of a model to quantify the number of corneas potentially saved. Results: Studies on splitting corneal donor tissue have demonstrated that up to 5 recipients may benefit from 1 donor scleral button. The impact of splitting donor tissue may provide a saving of up to 25.3% of donor graft tissue. Conclusions: Splitting and preparing the donor tissue within an eye bank will improve tissue validation and donor tissue availability and may increase surgeon efficiency
Free-floating DMEK in the host anterior chamber: Surgical management
No full textPurpose: To describe a method to visualize and manage a completely detached Descemet membrane endothelial keratoplasty (DMEK) tissue scroll in the anterior chamber. Methods: A 56-year-old male patient with pseudophakic bullous keratopathy, who underwent uncomplicated DMEK surgery, had a complete graft detachment diagnosed at 1-week follow-up. The graft was reattached using a new technique, that is, the free-floating graft was stained in the anterior chamber with trypan blue, immediately followed by air injection to separate the host stroma from the dye. The stained DMEK graft was opened by gentle tapping and attached to the host stroma by air tamponade. Result: This technique allowed sufficient staining of DMEK tissue to further evaluate and correct the graft orientation inside the anterior chamber without compromising the stroma. The DMEK graft was attached 1 week after the reattachment procedure. The cornea cleared confirming the functionality of the endothelial cells. Conclusions: The technique described may be useful in the cases of complete detachment of DMEK tissue and poor visualization of the DMEK tissue orientation. Staining with trypan blue under a “protective” air bubble can provide sufficient visualization to ensure the unfolding of DMEK tissue and reduce the risk of host stromal staining
Stability of Sb-Te layered structures: First-principles study
No full textUsing an effective one-dimensional cluster expansion in combination with first-principles electronic structure calculations we have studied the energetics and electronic properties of Sb-Te layered systems. For a Te concentration between 0 and 60 at. % an almost continuous series of metastable structures is obtained consisting of consecutive Sb bilayers next to consecutive Sb2Te3 units, with the general formula (Sb2)n(Sb2Te3)m (n,m=1,2,...). Between 60 and 100 at. % no stable structures are found. We account explicitly for the weak van der Waals bonding between Sb bilayers and Sb2Te3 units by using a recently developed functional, which strongly improves the interlayer bonding distances. At T=0 K, no evidence is found for the existence of two separate single-phase regions ? and ? and a two-phase region ?+?. Metastable compounds with a Te concentration between 0 and 40 at. % are semimetallic, whereas compounds with a Te concentration between 50 and 60 at. % are semiconducting. Compounds with an odd number of Sb layers are metallic and have a much higher formation energy than those with an even number of consecutive Sb layers, thereby favoring the formation of Sb bilayers.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Legal and Financial Problems of International Joint Custody of Children
No full textThe aim of this article is to analyze very interesting and currently up-to-date area of children living in international joint custody from the legal and financial point of view. This covers the situation when custody of a child is awarded to both parents living in different states of the European Union (or also other states). The number of marriages contracted between Czech nationals and foreign nationals and also between nationals from two different states (not necessarily inside European Union) increases every year while free movement of people is a real practice today. Because these international marriages are becoming more common they bring new problems that must be solved by contemporary law. This regulation needs to result from the knowledge of the children psychology that is affecting family law the most but also has its practical aspects in the area of taxation and payment issues that will be analyzed deeply as well.juridical problems, financial problems, international joint custody, family.
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