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23: Minor Families

Vacante, V. CABI PDF

23   Minor Families

This chapter includes mites in five families (Dolichocybidae,

Siteroptidae, Pygmephoridae, Scutacaridae, Microdispidae) that have in common a capacity to be either directly or indirectly injurious to mushrooms.

The Family Dolichocybidae Mahunka

Morphological characteristics, systematics and bio-ecology

The Dolichocybidae are small mites that are 100–280 μm long.

The prodorsal shield of the female lacks anterolateral stigmata and the associated tracheae; it has 2–3 pairs of setiform setae that may or may not have anterolateral bothridia with capitate sensilla (the normal scapular setae in the male). The prodorsum and the tergite C are normal in form, without wing-like expansions. In the genus Formicomotes Sevastyanov, the opisthosomal tergites C, D and EF are distinct, while the segment H may be consolidated with the pseudoanal segment Ps, and the aggenital region Ag into the undivided plate HPsAg located ventrally

(Magowski, 1988). The female has a small genital aperture, with 1–3 pairs of small or vestigial genital setae (g1–3) (Figs 23.1 and 23.2), which are sometimes absent, and 1 pair of aggenital setae (ag). Species of the genus Dolichocybe Krantz show tergites C, D, EF and Ps distinctly (Khaustov, 2006a). The tergites

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17: The Diffusion and Impact of Improved Food Crop Varieties in Sub-Saharan Africa

Walker, T.S. CABI PDF

17 

The Diffusion and Impact of Improved

Food Crop Varieties in Sub-Saharan Africa

K. Fuglie* and J. Marder

Economic Research Service, US Department of Agriculture and Department of

Agricultural and Resource Economics, University of California, Davis, USA

Introduction

The Diffusion and Impact of Improved Varieties in Africa (DIIVA) data on the adoption of improved crop varieties in sub-Saharan Africa (SSA)1 tell a confounding story. On the one hand, there has been significant progress over the past decade in disseminating improved crop cultivars to farmers. By 2010, total area sown to improved varieties of food crops exceeded 37 million hectares

(mha), more than double the estimated area in

2000 (Walker et al., 2014). On the other hand, even this achievement represented only 35% of area planted to these crops in the countries included in the DIIVA surveys.2 In most cases, the rate of diffusion of new crop varieties appears to have been quite slow. Moreover, the impact of crop variety adoption on agricultural productivity in SSA is not well documented. Because the speed of diffusion of new technology is likely to be correlated with its profitability, the slow pace of diffusion in SSA suggests that the productivity impact of improved crop varieties may be limited.

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4. Connecting the Drops: The Wider Human and Environmental Costs

Nicholas A. Robins Indiana University Press ePub

In order to gauge the health effects of mercury exposure on the residents and workers of Huancavelica and Potosí, it is necessary to understand how a multitude of dynamic factors interact. These include the amount of mercury and silver actually produced, how and under what climatic conditions quicksilver was lost to the atmosphere and waterways, and the effects of elemental mercury on people and animals when it is absorbed through different means. Fortunately, the Spanish authorities maintained detailed records concerning mercury and silver production, and contemporaries described the characteristics and inefficiencies of the respective refining processes, as well as the issue of contraband. By integrating the historical record with modern air-dispersion modeling and current medical knowledge of mercury’s effects, we can approximate the nature and range of the human and ecological effects that mining had at different times during the colonial period.

A Tremulous Toxin

Although mercury has no known use in the human body, it is present in minute quantities in the soil we cultivate and the air we breathe. As an element, designated as Hg in the periodic table, mercury can neither be created nor destroyed, and it has been found in every continent, and even on the moon. There are two sources of this element in the environment: those released through natural weathering processes of mercury-containing rock, and man-made, or anthropogenic, sources. Today, the latter are usually associated with electricity production, industrial applications and byproducts, and municipal and medical waste incineration.1

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9 Extinction

Fariña, Richard A. ePub

9.1. Size trends of large-sized South American mammals during the Cenozoic.

Based on Vizcaíno et al. (2012)

 

It might be said that humans should be as concerned with the extinction of species as much as with death. They are expressions of the same phenomenon at different scales of the hierarchy of life. To add appeal to the subject, the suggestions of extraterrestrial causes, such as asteroid or comet impacts, first to explain the demise of nonavian dinosaurs and then other groups of organisms, are in marked contrast to the more traditional models, such as gradual climate change, advanced to make sense of extinction (Alvarez et al., 1980; Pope et al., 1996). Although science strives for consensus (most scientists today accept that a single extraterrestrial impact scenario was the main trigger leading to the end of nonavian dinosaurs), it seldom achieves unanimity: Keller et al. (2009) found evidence in the Brazos River, Texas, USA, that the extinction occurred over several hundred thousand years at the end of the Cretaceous, a hypothesis recently strengthened by the identification of a second crater in Ukraine (Jolley et al., 2010). In any case, such events serve as strong reminders that a catastrophe from the far reaches of outer space and far beyond our collective human experience has occurred in the geologic past and that, given time, will occur again. The recent controversies and debates over which models best explain the nearly wholesale disappearance of organisms is a main reason why the study of mass extinctions has since experienced a surge of interest, both among scientists and the general public, and new ideas are being developed to understand causes, processes, and patterns.

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6: Developing Staff

Crafer, K CABI PDF

6 

Developing Staff

People are still the driving force behind any organization. Even if a department does not have direct contact with the purchasing customer, they still have a wide range of ‘internal’ customers within the organization with whom they interact.

The efficiency of all these interactions has a dramatic effect upon the success or failure of the business.

The challenge with any form of staff development within a business is calculating the financial benefits. It is easy to define the costs of staff development, through the collation of invoices and measurement of time spent off the job, whereas the improvements to production are less easy to measure. For organizations where there is a pressure on cash flow, the budget for personal development is an easy target as there are fewer directly measurable gains – the Return on

Investment (ROI; Kaufman and Hotchkiss, 2006).

However, lack of skills can bring a number of inefficiencies into an organization; while these are not easily measured, all combine together to prevent the organization from working at its full effectiveness.

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