Cosmic ray anisotropies at high energies

The directional anisotropies of the energetic cosmic ray gas due to the relative motion between the observers frame and the one where the relativistic gas can be assumed isotropic is analyzed. The radiation fluxes formula in the former frame must follow as the Lorentz invariance of dp/E, where p, E are the 4-vector momentum-energy components; dp is the 3-volume element in the momentum space. The anisotropic flux shows in such a case an amplitude, in a rotating earth, smaller than the experimental measurements from say, EAS-arrays for primary particle energies larger than 1.E(14) eV. Further, it is shown that two consecutive Lorentz transformations among three inertial frames exhibit the violation of dp/E invariance between the first and the third systems of reference, due to the Wigner rotation. A discussion of this result in the context of the experimental anisotropic fluxes and its current interpretation is given

Quantum Hall states under conditions of vanishing Zeeman energy

We report on magneto-transport measurements of a two-dimensional electron gas confined in a Cd$_{0.997}$Mn$_{0.003}$Te quantum well structure under conditions of vanishing Zeeman energy. The electron Zeeman energy has been tuned via the $s-d$ exchange interaction in order to probe different quantum Hall states associated with metallic and insulating phases. We have observed that reducing Zeeman energy to zero does not necessary imply the disappearing of quantum Hall states, i.e. a closing of the spin gap. The spin gap value under vanishing Zeeman energy conditions is shown to be dependent on the filling factor. Numerical simulations support a qualitative description of the experimental data presented in terms of a crossing or an avoided-crossing of spin split Landau levels with same orbital quantum number $N$

Barriers to Protection at Home and Abroad: Mexican Victims of Domestic Violence and the Violence Against Women Act

Undocumented domestic violence victims face many challenges in proving they will suffer extreme hardship if deported. Heralded as the most significant legislation to aid victims of domestic violence, the Violence Against Women Act of 1994 (“VAWA”) recognized two main ideas. First, domestic violence is a serious national problem in the United States. Second, the undocumented immigration status of victims and their fear of deportation exacerbates domestic abuse. VAWA commands that immigration laws remedy, rather than perpetuate, violence in families of citizens and lawful permanent residents. However, requiring victims of domestic violence to prove they will suffer extreme hardship if deported is an entirely inappropriate eligibility standard for this class of immigrants. “Extreme hardship” is prone to interpretations which are unrelated to the problems and needs of domestic violence victims. In cases of battered immigrants, determinations must be based on the factors tied to domestic violence, including the nature and extent of abuse suffered by the victim and the victim’s need for the support of the U.S. social and legal systems. The extreme hardship standard serves no reasonable immigration-related purpose with regard to battered immigrants. Further, it is incompatible with an immigration policy favoring foreign nationals who meet the eligibility requirements to immigrate, and does not support a policy to end domestic violence. Ultimately, Congress failed in its responsibility to serve the interests of battered and abused immigrants by including the requirement of extreme hardship in order to attain legal status

Mexican Children of U.S. Citizens: “Viges Prin” and Other Tales of Challenges to Asserting Acquired U.S. Citizenship

Mexican children with a U.S. parent face both historic and current challenges in acquiring U.S. citizenship. Following changes in U.S. immigration law, the number of individuals removed from the United States has swelled dramatically. This campaign against non-citizens has led to the removal of United States citizens, particularly individuals who were born abroad but claim citizenship through a U.S. citizen parent. Citizens are caught in the middle of conflicting goals between government efforts to adjudicate claims to acquired U.S. citizenship and the focus on crime and national security interests. Even though many U.S. parents and their children born abroad are unaware of laws regulating acquired citizenship status, the government has taken few affirmative steps to advise likely candidates for citizenship. As such, children born abroad to U.S. parents are commonly deported or removed from the United States, sometimes repeatedly, despite the fact that they are U.S. citizens. The Department of Homeland Security must prioritize locating individuals who have claims to citizenship and provide concrete assurances that no U.S. citizen is detained or removed from the United States. The cost to each U.S. citizen who is subjected to removal is incalculable. Until Congress restores avenues for asserting claims to citizenship before immigration judges and for review of claims in federal districts courts, U.S. citizens will continue to be removed without full access to the means to assert and review their claims

Mexican Children of U.S. Citizens: “Viges Prin” and Other Tales of Challenges to Asserting Acquired U.S. Citizenship

Mexican children with a U.S. parent face both historic and current challenges in acquiring U.S. citizenship. Following changes in U.S. immigration law, the number of individuals removed from the United States has swelled dramatically. This campaign against non-citizens has led to the removal of United States citizens, particularly individuals who were born abroad but claim citizenship through a U.S. citizen parent. Citizens are caught in the middle of conflicting goals between government efforts to adjudicate claims to acquired U.S. citizenship and the focus on crime and national security interests. Even though many U.S. parents and their children born abroad are unaware of laws regulating acquired citizenship status, the government has taken few affirmative steps to advise likely candidates for citizenship. As such, children born abroad to U.S. parents are commonly deported or removed from the United States, sometimes repeatedly, despite the fact that they are U.S. citizens. The Department of Homeland Security must prioritize locating individuals who have claims to citizenship and provide concrete assurances that no U.S. citizen is detained or removed from the United States. The cost to each U.S. citizen who is subjected to removal is incalculable. Until Congress restores avenues for asserting claims to citizenship before immigration judges and for review of claims in federal districts courts, U.S. citizens will continue to be removed without full access to the means to assert and review their claims

EPR and ferromagnetism in diluted magnetic semiconductor quantum wells

Motivated by recent measurements of electron paramagnetic resonance (EPR) spectra in modulation-doped CdMnTe quantum wells, [F.J. Teran {\it et al.}, Phys. Rev. Lett. {\bf 91}, 077201 (2003)], we develop a theory of collective spin excitations in quasi-two-dimensional diluted magnetic semiconductors (DMSs). Our theory explains the anomalously large Knight shift found in these experiments as a consequence of collective coupling between Mn-ion local moments and itinerant-electron spins. We use this theory to discuss the physics of ferromagnetism in (II,Mn)VI quantum wells, and to speculate on the temperature at which it is likely to be observed in n-type modulation doped systems.Comment: 4 pages, 1 figur

Management of Stroke with Pharmacological Fibrinolysis in an Emergency Department at a Level 2 Hospital in Central Ecuador

Introduction: A timely and organized response in the emergency department is crucial for the treatment of stroke with pharmacological fibrinolysis. Currently, few stroke patients have access to fibrinolytic treatment in Ecuador, as most hospitals lack a well-coordinated stroke response. This remains true at even the highest acuity (level 3) hospitals. In this study we report the initial results of the first code stroke and fibrinolysis pathway established in a level 2 public hospital in a small city (pop 300,000) in Ecuador.Objective: To develop an organized and coordinated pathway within the hospital for the correct diagnosis and treatment of patients with clinical presentation of stroke, starting with early identification of signs/symptoms and the activation of a specific pathway, which in turn improves the prognosis and the quality of life of acute ischemic stroke patients.Methods: This was a prospective, longitudinal, descriptive study of patients presenting with stroke symptoms, for whom a code stroke and red triage priority was applied in the emergency department of Hospital General Docente Ambato in the first three months of 2019. To be eligible for thrombolysis, patients had to arrive within 4.5 hours of symptom onset and not have any contraindications to thrombolysis.Results: 30 patients arrived at the emergency department with stroke symptoms, and in each case a code stroke was activated upon arrival to the emergency department. The mean age of patients was 66.63 years, and 15 patients were male (50%). 19 patients (63%) arrived within 4.5 hours of symptom onset, of which 8 patients (42%) had no contraindication and received thrombolysis. The mean door-to-needle time was 66 minutes.Conclusions: This study demonstrates that it is feasible to establish a code stroke and fibrinolysis treatment pathway in level 2 hospitals in Ecuador. Many other hospitals in the country could establish similar treatment protocols and improve their management of ischemic stroke patients

Tailoring magnetic anisotropy in epitaxial half metallic La0.7Sr0.3MnO3 thin films

We present a detailed study on the magnetic properties, including anisotropy, reversal fields, and magnetization reversal processes, of well characterized half-metallic epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown onto SrTiO3 (STO) substrates with three different surface orientations, i.e. (001), (110) and (1-18). The latter shows step edges oriented parallel to the [110] (in-plane) crystallographic direction. Room temperature high resolution vectorial Kerr magnetometry measurements have been performed at different applied magnetic field directions in the whole angular range. In general, the magnetic properties of the LSMO films can be interpreted with just the uniaxial term with the anisotropy axis given by the film morphology, whereas the strength of this anisotropy depends on both structure and film thickness. In particular, LSMO films grown on nominally flat (110)-oriented STO substrates presents a well defined uniaxial anisotropy originated from the existence of elongated in-plane [001]-oriented structures, whereas LSMO films grown on nominally flat (001)-oriented STO substrates show a weak uniaxial magnetic anisotropy with the easy axis direction aligned parallel to residual substrate step edges. Elongated structures are also found for LSMO films grown on vicinal STO(001) substrates. These films present a well-defined uniaxial magnetic anisotropy with the easy axis lying along the step edges and its strength increases with the LSMO thickness. It is remarkable that this step-induced uniaxial anisotropy has been found for LSMO films up to 120 nm thickness. Our results are promising for engineering novel half-metallic magnetic devices that exploit tailored magnetic anisotropy.Comment: 10 pages, 10 figures, 1 tabl

Structural behaviour and design criteria of under-deck cable-stayed bridges subjected to seismic action

SUMMARY: Under-deck cable-stayed bridges are very effective structural systems for which the strong contribution of the stay cables under live loading allows for the design of very slender decks for persistent and transient loading scenarios. Their behaviour when subjected to seismic excitation is investigated herein and a set of design criteria are presented that relate to the type and arrangement of bearings, the number and configuration of struts, and the transverse distribution of stay cables. The nonlinear behaviour of these bridges when subject to both near-field and far-field accelerograms has been thoroughly investigated through the use of incremental dynamic analyses. An intensity measure that reflects the pertinent contributions to response when several vibration modes are activated was proposed and is shown to be effective for the analysis of this structural type. The under-deck cable-stay system contributes in a very positive manner to reducing the response when the bridges are subject to very strong seismic excitation. For such scenarios, the reduction in the stiffness of the deck because of crack formation, when prestressed concrete decks are used, mobilises the cable system and enhances the overall performance of the system. Sets of natural accelerograms that are compliant with the prescriptions of Eurocode 8 were also applied to propose a set of design criteria for this bridge type in areas prone to earthquakes. Particular attention is given to outlining the optimal strategies for the deployment of bearings