578 research outputs found
Effective action for a quantum scalar field in warped spaces
We investigate the one-loop corrections at zero, as well as finite
temperature, of a scalar field taking place in a braneworld motived warped
background. After to reach a well defined problem, we calculate the effective
action with the corresponding quantum corrections to each case.Comment: 10 pages, to appear in The European Physical Journal
On the bilinear covariants associated to mass dimension one spinors
In this paper we approach the issue of Clifford algebra basis deformation,
allowing for bilinear covariants associated to Elko spinors which satisfy the
Fierz-Pauli-Kofink identities. We present a complete analysis of covariance,
taking into account the involved dual structure associated to Elko. Moreover,
the possible generalizations to the recently presented new dual structure are
performed.Comment: 9 pages, 0 figure
Biomarkers for precision immunotherapy in the metastatic setting: Hope or reality?
Precision immunotherapy is a crucial approach to improve the efficacy of anti-cancer treatments, particularly in the metastatic setting. In this respect, accurate patient selection takes advantage of the multidimensional integration of patients' clinical information and tumour-specific biomarkers status. Among these biomarkers, programmed death-ligand 1, tumour-infiltrating lymphocytes, microsatellite instability, mismatch repair and tumour mutational burden have been widely investigated. However, novel tumour-specific biomarkers and testing methods will further improve patients' outcomes. Here, we discuss the currently available strategies for the implementation of a precision immunotherapy approach in the clinical management of metastatic solid tumours and highlight future perspectives
Hurricane Hugo: Damage to a Tropical Rain Forest in Puerto Rico
Hurricane Hugo of September 1989 caused severe damage to the rain forest in the north-east corner of Puerto Rico. We assessed the severity of damage distributed in space, species, and size-classes of trees in the Bisley Watersheds of the Luquillo Experimental Forest. We analyzed pre- and post-hurricane data for vegetation from transects established in 1987 and 1988. The severity of damage was significantly greater in valleys than on ridges and slopes. All the species except Dacryodes excelsa, Sloanea berteriana, and Guarea guidonia showed 100% severe damage. Large trees (\u3e 70 cm DBH) were highly susceptible to hurricane damage, but there was no clear pattern in the small size-classes. D. excelsa (tabonuco) was the most resistant to damage by the hurricane. Tabonuco which has extensive root-grafts and root anchorage to bedrock and subsurficial rocks, apparently can survive frequent hurricanes and continue as a dominant species in this montane tropical rain forest. The high frequency of hurricanes, which can override other ecological and topographic factors, may largely determine the overall spatial pattern of species in this rain forest
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Radiochemical Analysis Methodology for uranium Depletion Measurements
This report provides sufficient material for a test sponsor with little or no radiochemistry background to understand and follow physics irradiation test program execution. Most irradiation test programs employ similar techniques and the general details provided here can be applied to the analysis of other irradiated sample types. Aspects of program management directly affecting analysis quality are also provided. This report is not an in-depth treatise on the vast field of radiochemical analysis techniques and related topics such as quality control. Instrumental technology is a very fast growing field and dramatic improvements are made each year, thus the instrumentation described in this report is no longer cutting edge technology. Much of the background material is still applicable and useful for the analysis of older experiments and also for subcontractors who still retain the older instrumentation
Effects of Hurricane Disturbance on Stream Water Concentrations and Fluxes in Eight Tropical Forest Watersheds of the Luquillo Experimental Forest, Puerto Rico
Stream water chemistry responds substantially to watershed disturbances, but hurricane effects have not been extensively investigated in tropical regions. This study presents a long-term (2.5-11 y) weekly record of stream water chemistry on eight forested watersheds (catchment basins) in the Luquillo Mountains of Puerto Rico. This includes a period before and at least 2 y after the disturbance caused by the 1989 Hurricane Hugo. Nitrate, potassium and ammonium concentrations increased after the hurricane and remained elevated for up to 2 y. Sulphate, chloride, sodium, magnesium and calcium showed smaller relative significant changes. Average stream water exports of potassium, nitrate and ammonium increased by 13.1, 3.6 and 0.54 kg ha -1 y -1 in the first post-hurricane year across all watersheds. These represent increases of 119, 182 and 102 of record. The increased stream outputs of potassium and nitrogen in the first 2 y post-hurricane are equivalent to 3of the hurricane-derived plant litter. Effects of hurricanes on tropical stream water potassium and nitrogen can be greater than those caused by canopy gaps or limited forest cutting, but less than those following large-scale deforestation or fire
Some interesting features of new massive gravity
A proof that new massive gravity - the massive 3D gravity model proposed by
Bergshoeff, Hohm and Townsend (BHT) - is the only unitary system at the tree
level that can be constructed by augmenting planar gravity through the
curvature-squared terms, is presented. Two interesting gravitational properties
of the BHT model, namely, time dilation and time delay, which have no
counterpart in the usual Einstein 3D gravity, are analyzed as well.Comment: Submitted to Classical and Quantum Gravit
The impact of forest regeneration on streamflow in 12 mesoscale humid tropical catchments
Although regenerating forests make up an increasingly large portion of humid tropical landscapes, little is known of their water use and effects on streamflow (Q). Since the 1950s the island of Puerto Rico has experienced widespread abandonment of pastur
Mitochondrial myopathy and comorbid major depressive disorder. effectiveness of dTMS on gait and mood symptoms
Background: Mitochondrial myopathies (MMs) often present with leukoencephalopathy and psychiatric symptoms, which do not respond to or worsen with psychiatric drugs. Case report: A 67-year-old woman with a 10-year history of probable chronic progressive external ophthalmoplegia, an MM, had drug-resistant, anxious-depressive symptoms. Since she had never had seizures, we proposed 20 sessions of deep transcranial magnetic stimulation (dTMS) for her depression. Surprisingly, besides the expected improvement of depression, we observed marked improvement of movement disorder that lasted as long as the patient was undergoing dTMS. She also improved her performance on neuropsychological tests of executive function and cognitive speed. Depressive symptom improvement was persistent, while anxiety symptoms recurred after the end of the sessions.
Conclusions: dTMSmay be an alternative antidepressant strategy in patients withMMs, provided that they are free from seizures. The mechanism of improvement of motor disturbance may relate to dorsolateral prefrontal cortex stimulation and improved executive function and needs further investigation
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