A brief introduction to molecular orbital theory of simple polyatomic molecules for undergraduate chemistry students

A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.

Leibniz's theory of bodies: monadic aggregates, phenomena, or both?

Leibniz's conception of bodies seems to be a puzzling theory. Bodies are seen as aggregates of monads and as wellfounded phenomena. This has initiated controversy and unending discussions. The paper attempts to resolve the apparent inconsistencies by a new and formally spirited reconstruction of Leibniz's theory of monads and perception, on the one hand, and a (re-)formulation and precisation of his concept of preestablished harmony, on the other hand. Preestablished harmony is modelled basically as a covariation between the monadic and the ideal realm.

The relation between the general maxim of causality and the principle of uniformity in hume's theory of knowledge

ABSTRACT When Hume, in the Treatise on Human Nature, began his examination of the relation of cause and effect, in particular, of the idea of necessary connection which is its essential constituent, he identified two preliminary questions that should guide his research: (1) For what reason we pronounce it necessary that every thing whose existence has a beginning should also have a cause and (2) Why we conclude that such particular causes must necessarily have such particular effects? (1.3.2, 14-15) Hume observes that our belief in these principles can result neither from an intuitive grasp of their truth nor from a reasoning that could establish them by demonstrative means. In particular, with respect to the first, Hume examines and rejects some arguments with which Locke, Hobbes and Clarke tried to demonstrate it, and suggests, by exclusion, that the belief that we place on it can only come from experience. Somewhat surprisingly, however, Hume does not proceed to show how that derivation of experience could be made, but proposes instead to move directly to an examination of the second principle, saying that, "perhaps, be found in the end, that the same answer will serve for both questions" (1.3.3, 9). Hume's answer to the second question is well known, but the first question is never answered in the rest of the Treatise, and it is even doubtful that it could be, which would explain why Hume has simply chosen to remove any mention of it when he recompiled his theses on causation in the Enquiry concerning Human Understanding. Given this situation, an interesting question that naturally arises is to investigate the relations of logical or conceptual implication between these two principles. Hume seems to have thought that an answer to (2) would also be sufficient to provide an answer to (1). Henry Allison, in his turn, argued (in Custom and Reason in Hume, p. 94-97) that the two questions are logically independent. My proposal here is to try to show that there is indeed a logical dependency between them, but the implication is, rather, from (1) to (2). If accepted, this result may be particularly interesting for an interpretation of the scope of the so-called "Kant's reply to Hume" in the Second Analogy of Experience, which is structured as a proof of the a priori character of (1), but whose implications for (2) remain controversial.

The theory of constraints in manufacturing

In this paper, a systematic and quantitative view is presented for the application of the theory of constraints in manufacturing. This is done employing the operational research technique of mathematical programming. The potential of the theory of constraints in automated manufacturing is demonstrated.

Cytokines as determinants of disease and disease interactions

The immune response to pathogens results in both host resistance and immunopathology. Cytokines and in particular those lymphokines produced by Th1 and Th2 cells play a key role in determining the balance between these two immunologic outcomes. Recent data suggest that interleukin-10, a product of both Th2 cells and macrophages, protects the host against excessive immunopathology. The cytokine environment generated by different pathogens may also influence the course and outcome of infections with unrelated organisms. This relationship may be particularly important in the case of HIV-1 where prior Th1 or Th2 biases established by helminth or intracellular infections may influence either initial viral susceptibility or drive progression to AIDS through immune activation

MFG-E8, a clearance glycoprotein of apoptotic cells, as a new marker of disease severity in chronic obstructive pulmonary disease

Milk fat globule epidermal growth factor 8 (MFG-E8) is an opsonin involved in the phagocytosis of apoptotic cells. In patients with chronic obstructive pulmonary disease (COPD), apoptotic cell clearance is defective. However, whether aberrant MFG-E8 expression is involved in this defect is unknown. In this study, we examined the expression of MFG-E8 in COPD patients. MFG-E8, interleukin (IL)-1β and transforming growth factor (TGF)-β levels were measured in the plasma of 96 COPD patients (93 males, 3 females; age range: 62.12±10.39) and 87 age-matched healthy controls (85 males, 2 females; age range: 64.81±10.11 years) using an enzyme-linked immunosorbent assay. Compared with controls, COPD patients had a significantly lower plasma MFG-E8 levels (P<0.01) and significantly higher plasma TGF-β levels (P=0.002), whereas there was no difference in plasma IL-1β levels between the two groups. Moreover, plasma MFG-E8 levels decreased progressively between Global Initiative for Chronic Obstructive Lung Disease (GOLD) I and GOLD IV stage COPD. Multiple regression analysis showed that the forced expiratory volume in 1 s (FEV1 % predicted) and smoking habit were powerful predictors of MFG-E8 in COPD (P<0.01 and P=0.026, respectively). MFG-E8 was positively associated with the FEV1 % predicted and negatively associated with smoking habit. The area under the receiver operating characteristic curve was 0.874 (95% confidence interval: 0.798-0.95; P<0.01). Our findings demonstrated the utility of MFG-E8 as a marker of disease severity in COPD and that cigarette smoke impaired MFG-E8 expression in these patients.

Has social justice any legitimacy in Kant's theory of right? The empirical conditions of the legal state as a civil union

This paper aims at shedding light on an obscure point in Kant's theory of the state. It discusses whether Kant's rational theory of the state recognises the fact that certain exceptional social situations, such as the extreme poverty of some parts of the population, could request institutional state support in order to guarantee the attainment of a minimum threshold of civil independence. It has three aims: 1) to show that Kant's Doctrine of Right can offer solutions for the complex relation between economics and politics in our present time; 2) to demonstrate the claim that Kant embraces a pragmatic standpoint when he tackles the social concerns of the state, and so to refute the idea that he argues for an abstract conception of politics; and 3) to suggest that a non-paternalistic theory of rights is not necessarily incompatible with the basic tenets of a welfare state.