The Immanent Contingency of Physical Laws in Leibniz’s Dynamics

This paper focuses on Leibniz’s conception of modality and its application to the issue of natural laws. The core of Leibniz’s investigation of the modality of natural laws lays in the distinction between necessary, geometrical laws on the one hand, and contingent, physical laws of nature on the other. For Leibniz, the contingency of physical laws entailed the assumption of the existence of an additional form of causality beyond mechanical or efficient ones. While geometrical truths, being necessary, do not require the use of the principle of sufficient reason, physical laws are not strictly determined by geometry and therefore are logically distinct from geometrical laws. As a consequence, the set of laws that regulate the physical laws could have been created otherwise by God. However, in addition to this, the contingency of natural laws does not consist only in the fact that God has chosen them over other possible ones. On the contrary, Leibniz understood the status of natural laws as arising from the action internal to physical substances. Hence the actuality of physical laws results from a causal power that is inherent to substances rather than being the mere consequence of the way God arranged the relations between physical objects. Focusing on three instances of Leibniz’s treatment of contingency in physics, this paper argues that, in order to account for the contingency of physical laws, Leibniz maintained that final causes, in addition to efficient and mechanical ones, must operate in physical processes and operations

Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior

The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th+U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is highlighted.Comment: 12 pages, including 6 figure

Structural Characteristics of Pennisetum Americanum (Pearl Millet) Using Scanning Electron and Fluorescence Microscopy

Fluorescence bright field and scanning electron microscopy were used to characterize the structure of selected mature pearl millet caryopses from the World Germplasm Collection. Kernel shape (globose, lanceolate, obovate and hexagonal). kernel endosperm color (while. yellow and grey) and external appearance (color) of the samples were documented for 96 varieties. Color of the pearl millet kernel was due to the combined effects of pigmentation in the pericarp. aleurone and endosperm. as well as the pericarp thickness. White kernels had few pigmented areas. yellow kernels had pigments primarily in the epicarp and endosperm. and brown kernels had pigments in the epicarp. aleurone and endosperm. The majority of white, yellow and brown kernels had a thick pericarp. Purple kernels also had pigments in the epicarp, aleurone and endosperm, but had a thin pericarp. Grey kernels had pigments in the aleurone and endosperm. and had a thin pericarp. The periicarp was different from that found in sorghum in that the epicarp cells could be large, round, multilayered and full of pigments, or flat. single-layered and empty. The seed coat and a leurone layer were similar to those found in sorghum. Phytin and nicotinic acid were present in the germ. B-D-glucans were present in the cell walls in the endosperm

Ozone technology in the post-harvest storage environment- a comparison of efficacy of high doses of ozone to insects treated under laboratory conditions and field conditions

Efficacy experiments were conducted to determine the ozone concentration (C) and treatment time (T) needed to effectively kill adult stages of red flour beetle (i>Tribolium castaneum) and maize weevil (Sitophilus zeamais). Under laboratory conditions, insects were exposed to concentrations of ozone ranging from 50 to 1800 ppm for 30 and 60 min. After treatment, insect mortality was scored, and if 100% mortality was not reached, more treatment-time was added in 30 min intervals at 1800 ppm. For both species, 100% mortality was reached after treatment at 1800 ppm for 120 min, which equates to a concentration*time (CT) product of 216,000 ppm.min. A similar CT product was attained under field conditions with a prototype auger designed to treat moving streams of grain with ozone during transfer. In field tests, 100% mortality was achieved for both insect species after a treatment of 47,000 ppm ozone for 6 min (CT = 282,000 ppm.min). The results indicate that CT values obtained in laboratory experiments correlated wll with those from field experiments. Based on these results, we now can calculate ozone concentration and auger length needed to treat grain in a fast-moving stream. Keywords: Ozone, Maize weevil, Sitophilus zeamais, Red flour beetle, Tribolium castaneu

Research on armadillos: A review and prospectus

A detailed analysis of 1,039 scientific studies of extant armadillos (Xenarthra: Cingulata, Dasypodidae) published in the last 25 years (1989-2013) revealed substantial biases in coverage, including taxonomically, the locales where field studies were conducted, and in the topics investigated. Examination of the number of other publications that cited each paper revealed that 470 (45%) papers had been cited no more than 10 times, 249 (24%) had never been cited, and 112 (11%) were not even found in the Google Scholar database. The most heavily cited papers were molecular phylogenetic analyses that often used tissues from one or more species of armadillo but were not about the animals per se. Thus, it appears that research on armadillos is plagued by numerous gaps in coverage and is not reaching a wide audience. These data indicate obvious opportunities for future research. In addition, recent findings suggest that even relatively well-studied phenomena may require reexamination. Here, we review recent advances in the study of armadillos and highlight promising areas for future work. One critical need is for a thorough systematic revision of Dasypodidae to be completed. This will make it possible to prioritize those species and populations most in need of study. Additionally, more long-term field studies of populations of marked individuals are required. Although there are many important and interesting questions waiting to be answered, the small number of researchers currently conducting studies of armadillos, particularly in the wild, means that progress will be slow.Facultad de Ciencias Naturales y Muse

Teleology and Realism in Leibniz's Philosophy of Science

This paper argues for an interpretation of Leibniz’s claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibniz’s fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibniz’s thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibniz’s use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibniz’s use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz

Mutation analysis of HIF prolyl hydroxylases (PHD/EGLN) in individuals with features of phaeochromocytoma and renal cell carcinoma susceptibility

Germline mutations in the von Hippel–Lindau disease (VHL) and succinate dehydrogenase subunit B (SDHB) genes can cause inherited phaeochromocytoma and/or renal cell carcinoma(RCC). Dysregulation of the hypoxia-inducible factor (HIF) transcription factors has been linked to VHL and SDHB-related RCC; both HIF dysregulation and disordered function of a prolyl hydroxylase domain isoform 3 (PHD3/EGLN3)-related pathway of neuronal apoptosis have been linked to the development of phaeochromocytoma. The 2-oxoglutarate-dependent prolyl hydroxylase enzymes PHD1 (EGLN2), PHD2 (EGLN1) and PHD3 (EGLN3) have a key role in regulating the stability of HIF-a subunits (and hence expression of the HIF-a transcription factors). A germline PHD2 mutation has been reported in association with congenital erythrocytosis and recurrent extra-adrenal phaeochromocytoma. We undertook mutation analysis of PHD1, PHD2 and PHD3 in two cohorts of patients with features of inherited phaeochromocytoma (nZ82) and inherited RCC (nZ64) and no evidence of germline mutations in known susceptibility genes. No confirmed pathogenic mutations were detected suggesting that mutations in these genes are not a frequent cause of inherited phaeochromocytoma or RCC