Classical Morphology of Plants as an Elementary Instance of Classical Invariant Theory

It has long been known that structural chemistry shows an intriguing correspondence with Classical Invariant Theory (CIT). Under this view, an algebraic binary form of the degree n corresponds to a chemical atom with valence n and each physical molecule or ion has an invariant-theoretic counterpart. This theory was developed using the Aronhold symbolical approach and the symbolical processes of convolution/transvection in CIT was characterized as a potential “accurate morphological method”. However, CIT has not been applied to the formal morphology of living organisms. Based on the morphological interpretation of binary form, as well as the process of convolution/transvection, the First and Second Fundamental Theorems of CIT and the Nullforms of CIT, we show how CIT can be applied to the structure of plants, especially when conceptualized as a series of plant metamers (phytomers). We also show that the weight of the covariant/invariant that describes a morphological structure is a criterion of simplicity and, therefore, we argue that this allows us to formulate a parsimonious method of formal morphology. We demonstrate that the “theory of axilar bud” is the simplest treatment of the grass seedling/embryo. Our interpretations also represent Troll's bauplan of the angiosperms, the principle of variable proportions, morphological misfits, the basic types of stem segmentation, and Goethe's principle of metamorphosis in terms of CIT. Binary forms of different degrees might describe any repeated module of plant organisms. As bacteria, invertebrates, and higher vertebrates are all generally shared a metameric morphology, wider implications of the proposed symmetry between CIT and formal morphology of plants are apparent

Dynamics of the temperature-humidity index in the Mediterranean basin

The study was aimed at describing the temperature humidity index (THI) dynamics over the Mediterranean basin for the period 1951–2007. Results indicated that several areas of the basin present summer THI values which were unfavorable to cow welfare and productivity, and that risk of heat stress for cows is generally greater in the countries of the south coast of the basin. Furthermore, THI data from the summer 2003 revealed that severe positive anomalies may impact areas normally characterized by a favorable climate for animal production. In conclusion, THI dynamics should be taken into careful consideration by farmers and policy makers operating in Mediterranean countries when planning investments in the sector of animal production. The investments should at least partially be directed towards implementation of adaptation measures, which may help to alleviate the impact of hot on farm animals welfare, performance and health. Lo studio ha lo scopo di descrivere le dinamiche dell’indice di temperature e umidità (THI) nel bacino del Mediterraneo per il periodo dal 1951 al 2077. I risultati ottenuti indicano che diverse aree del bacino del Mediterraneo presentano valori di THI sfavorevoli per il benessere e la produttività della vacca da latte, e che il rischio è superiore per i paese della costa sud del Mediterraneo. Inoltre, è stato evidenziato come periodi particolari quali ad esempio l’estate del 2003 hanno prodotto anomalie climatiche che possono impattare negativamente anche in aree in cui normalmente non si rilevano problemi di stress. In conclusione, le dinamiche del THI dovrebbero essere prese in considerazione dagli allevatori dell’area del Mediterraneo per la pianificazione della tipologia di investimenti nel campo delle produzioni animali. Gli investimenti dovrebbero, almeno in parte, prevedere misure di adattamento per alleviare l’impatto dello stress da caldo sul benessere, sulla salute e sulle performances degli animali allevati.L'articolo è disponibile sul sito dell'editore http://link.springer.com/journal/48