Economics, Biology, and Naturalism: Three Problems Concerning the Question of Individuality

The paper examines the ramifications of naturalism with regard to the question of individuality in economics and biology. Economic theory has to deal with whether households, firms, and states are individuals or are mere entities such as clubs, networks, and coalitions. Biological theory has to deal with the same question with regard to cells, organisms, family packs, and colonies. To wit, the question of individuality in both disciplines involves three separate problems: the metaphysical, phenomenist, and ontological. The metaphysical problem is concerned with purposeful action: Is the firm or organism exclusively the product of efficient causality (optimization) or is it motivated by final causality (purposefulness)? The phenomenist problem is interested in the substantiality of essences: Is the firm's or organism's scheme of institutions/traits deep or is it extraneous to identity? The ontological problem is related to the issue of reductionism: Is the behavior of lower-level organization governed by a pre-constituted entities or is it context-sensitive? The paper finds that theoretical differences run along the naturalist/anti-naturalist divide rather than along disciplinary specialization. Also, the paper finds that it is not inconsistent for the same theorist to be naturalist with regard to one problem and anti-naturalist with respect to the other two problems.     

Genetic polymorphisms of <Emphasis Type="Italic">T-1131C APOA5</Emphasis> and <Emphasis Type="Italic">ALOX5AP SG13S114</Emphasis> with the susceptibility of ischaemic stroke in Morocco

Ischaemic stroke is a multifactorial disease. Genetic polymorphisms involved in lipid, inflammatory and thrombotic metabolisms play an important role in the development of ischaemic stroke. The present study aimed to assess the relationship between T1131C APOA5 and SG13S114 ALOX5AP polymorphisms and the risk of ischemic stroke in 175 cases and 201 controls. Genotyping was performed by high resolution melting and polymerase chain reaction restriction fragment length polymorphism methods. In the case of T-1131C APOA5, a modest risk of ischaemic stroke was noticed with CC (OR: 2.86; 95% CI = 1.24–6.58; Pc = 0.039) and C allele (OR: 1.54; 95% CI = 1.01–2.33; Pc = 0.014). For SG13S114ALOX5AP, a significant association was observed among subjects with TT (OR: 2.57; 95% CI =1.49–4.83; Pc = 0.009) and T allele (OR: 1.59; 95% CI = 1.16–2.19; Pc = 0.008). According to the risk factors of ischaemic stroke, a positive correlation was observed only between SG13S114 variant of ALOX5AP gene and hypertension (Pc = 0.026). Despite lower sample size, T-1131C APOA5 and SG13S114 variants could be considered an independent genetic risk factor of ischaemic stroke in Moroccan population.     

Studies on the bacterial diseases of Sudan crops

New records are presented of bacterial diseases affecting the following weed plants: Heliotropium sudanicum, Rhynchosia memnonia, Vigna radiata, V. pubigera, Euphorbia acalyphoides and Phyllanthus niruri. Bacterial leaf blight of pigeon pea (Cajanus cajan) caused by Xanthomonas phaseoli f. cajani is reported for the first time from the Sudan. The causal bacteria, all of which belong to the genus Xanthomonas, are compared with related pathogens. The differences between these bacteria are considered of little diagnostic value. Pathogenically, they can be separated into three groups: (i) the Heliotropium pathogen; (ii) the bacteria affecting leguminous plants; and (iii) the bacteria affecting species of the family Euphorbiaceae. Because of the diversity in opinion on speciation in the genus Xanthomonas, two alternative proposals are put forward. In the first, Xanthomonas is considered a monotypic genus with X. campestris as the sole species. The pathogens reported in this work from previously unrecorded hosts, which proved to differ in pathogenicity from established ones, are considered to be new formae speciales. These are X. campestris f.sp. heliotropii from H. sudanicum, X. campestris f.sp. rhynchosiae from R. memnonia, X. campestris f.sp. vigna-radiatae from V. radiata, X. campestris f.sp. euphorbiae from E. acalyphoides and X. campestris f.sp. phyllanthii from P. niruri. The organism from V. pubigera is accordingly identified as X. campestris f.sp. vignicola. Other bacteria used for comparison are also reduced to ff.sp. of X. campestris. The other proposal is to lump together pathogens with overlapping host ranges in a single species that comprises a number of ff.sp. differing in pathogenicity. Thus the bacteria from leguminous plants are all considered to belong to X. phaseoli as previously suggested by Sabet. New ff.sp. are created for the pathogens from R. memnonia (X. phaseoli f.sp. rhynchosiae), and V. radiata (X. phaseoli f.sp. vigna-radiatae). The organism from V. pubigera is identified in this case as X. phaseoli f.sp. vignicola. The bacteria from members of the Euphorbiaceae are considered to belong to X. ricini on priority grounds. X. cassavae and X. poinsettiaecola which have been used for comparison are reduced to the ff.sp. X. ricini f.sp. cassavae and f.sp. poinsettiaecola respectively. Two new ff.sp. are created: for E. acalyphoides pathogen, X. ricini f.sp. euphorbiae and for P. niruri pathogen, X. ricini f.sp. phyllanthii. The creation of a new species (X. heliotropii sp.nov.) is proposed for the Heliotropium pathogen. The present study shows that many weed plants may be affected with new bacterial strains that can also infect cultivated crops.     

Olenekian (Early Triassic) bivalves from the Salt Range and Surghar Range,Pakistan

Abstract: Based on newly collected material from the uppermost Smithian and lower to middle Spathian (Olenekian, Lower Triassic) of the Salt Range and Surghar Range (Pakistan), 15 bivalve species belonging to 11 genera are described, including two new genera, Eobuchia and Dimorphoconcha, and one new species, Palaeoneilo? fortistriata. Eobuchia gen. nov. is placed in a new subfamily, the Eobuchiinae, which differs from the Buchiinae in having an almost planar and only moderately inclined or offset right anterior auricle. Inclination of the right anterior auricle is proposed as a synapomorphy of the revised suborder Monotidina, which includes the Buchiidae, Monotidae, Oxytomidae and, tentatively, the Dolponellidae. The Pseudomonotidae, Chaenocardiidae and Claraiidae are discussed as candidate ancestors of the Monotidina. Dimorphoconcha gen. nov., provisionally placed in the Limidae, is a morphologically unusual genus characterized by a globose shell centre and a strongly plicate fringe. Permophorus costatus, which was previously known exclusively from Permian strata, is reported from the Spathian of the Surghar Range. This record extends the range of P. costatus for at least 8 Myr and makes it the first reported Lazarus species, with an outage of more than 2 Myr after the end‐Permian mass extinction. Ten of 15 species recognized in this study have not been reported from other regions, which may indicate increasing provincialism towards the end of the Early Triassic, or, alternatively, reflect the still insufficient knowledge of benthic faunas from the epoch that followed the greatest crisis in the history of life.     

Abscisic acid concentrations and fluxes in droughted conifer saplings

We present the first study of abscisic acid (ABA) concentrations and fluxes in the xylem sap of conifers during a drought cycle. In both Pinus sylvestris and Picea sitchensis the concentration of ABA in the sap rose 11-fold as the drought progressed. There were clear diurnal trends in this concentration, which reached its maximum (6–8.ininol ABA m^?3) near the middle of the day. The fluxes of ABA were calculated by multiplying the xylem ABA concentration by the sap flow rate. The ABA fluxes in the droughted plants in the middle of the day were usually no higher than those of the controls, as a result of the very low sap flow in the droughted plants at that time. However, the ABA flux in the droughted plants was higher than in the controls in the morning, and we postulate that the stomata are responding to these ‘morning doses’ Stomatal conductance, g_s, could not be related statistically to leaf turgor or to the ABA flux. However, £s did display a negative exponential relationship with ABA concentration in the xylem. Pinus displayed more acclimation to drought than Picea, Its ABA concentration rose and its stomatal conductance fell at day 6 of the drought, as opposed to day 17 for Picea, and its osmotic potential fell during the drought treatment.     

Does Xylem Sap ABA Control the Stomatal Behaviour of Water-Stressed Sycamore (Acer pseudoplatanus L.) Seedlings?

Sycamore seedlings were grown with their root systems dividedequally between two containers. Water was withheld from onecontainer while the other container was kept well-watered. Effectsof soil drying on stomatal behaviour, shoot water status, andabscisic acid (ABA) concentration in roots, xylem sap and leaveswere evaluated. At 3 d, root ABA in the drying container increased significantly,while the root ABA in the unstressed container of the same plantsdid not differ from that of the control. The increase in rootABA was associated with the increase in xylem sap ABA and withthe decrease in stomatal conductance without any significantperturbation in shoot water status. At 7 d, despite the continuous increase in root ABA concentration,xylem sap ABA showed a marked decline when soil water contentwas depleted below 013 g g^–1. This reduction in xylemsap ABA coincided with a partial recovery of stomatal conductance.The results indicate that xylem sap ABA is a function of rootABA as well as the flow rate of water from roots to shoots,and that this ABA can be a sensitive indicator to the shootof the effect of soil drying. Key words: Acer pseudoplatanus L., soil drying, stomatal behaviour, xylem sap ABA     

Acclimation to Drought in Acer pseudoplatanus L. (Sycamore) Seedlings

A glasshouse experiment was conducted with well-watered andwater-stressed seedlings of sycamore (Acer pseudoplatanus L.)grown in soil columns. Water was withheld when the seedlingswere 82-d-old. Effects of soil drying on stomatal behaviour,water relations, xylem cavitation, and growth of leaves androots were evaluated. Stomatal conductance declined well before any observable changein bulk leaf water potentials, and was correlated with soilwater status. At seven weeks, osmotic potential had declinedby 0·51 MPa and 0·44 MPa at full and zero turgor,respectively. Drought significantly increased both bulk elasticmodulus and leaf dry weight to turgid weight ratio of water-stressedplants. Drought had no effect on relative water content at zeroturgor. Water cavitation in the xylem was detected as ultrasonic acousticemissions (AE). Water-stressed plants displayed significantlyhigher rates of AE than well-watered plants. Maximum rate ofAE coincided with the minimum level of stomatal conductanceand apparent rehydration of the leaves. Drought caused changes in the root distribution profile andit increased the root weight. The increase in root weight wasmainly due to a substantial shift in assimilates allocated infavour of roots with total biomass being unaffected. Leaf growthwas maintained for six weeks without any significant declinein expansion rate. However, the development of severe waterstress reduced both leaf production and expansion.