Seasonal changes in populations of Caulerpa taxifolia var. distichophylla in the Maltese Islands

Caulerpa taxifolia var. distichophylla, an alien alga in the Mediterranean Sea, was first recorded from the Maltese Islands in 2013. Initial observations suggested that it underwent complete frond regression in winter, possibly due to the colder temperatures. Since then it has spread rapidly and has become abundant in the infralittoral in some localities. The present two-year study on the Maltese populations indicates that the alga is able to resist low seawater temperatures during the winter and is not regressing completely, potentially increasing its ecological impact.peer-reviewe

Algal substratum preferences of the alien foraminiferan Amphistegina lobifera in shallow water

The Lessepsian foraminiferan Amphistegina lobifera is particularly numerous on algae in shallow water. We sampled foraminiferans from three algae (Cystoseira spp., Padina pavonica and Halopteris sp.) within the 0.75 - 2.0 m depth zone from five different sites around the island of Malta. There was a significant difference in the population density of live Amphistegina between the algae studied with Halopteris being preferred to Padina and with very sparse populations on Cystoseira.peer-reviewe

Competition Policy in Small Distant Open Economies: Some Lessons from the Economics Literature

New Zealand is a small open economy that is remote from all major markets. The smallness and remoteness of New Zealand combine to imply that this country has, at least quantitatively, distinctive features for the regulation of economic activity by competition law. The isolation and small size of the economy mean that typically all but exporting firms are small as judged on a world scale, and that domestic markets are small and generally highly concentrated. This paper reviews the economic literature on the implications of an economy’s size and isolation for competition law. The literature suggests that principles underlying competition law do not change for small economies, but that the application of competition law should be different. In small economies, low regulatory and tax barriers to trade dominate the importance of competition law for good economic performance of domestic markets. In these economies, competition law should focus on economic benefit/detriment evaluations of mergers and trade practices rather than rules of thumb of the sort based on measures of market structure and indicators of competition, or those aimed at prohibiting particular practices per se. Producers’ surplus should not be de-emphasised in the calculation of benefits and detriments in small economies; particularly for activities that relate in any way to (potential) export activity. For any economy, particularly in the presence of competition, cooperation enhances economic performance in specific circumstances. In small economies cooperation can be particularly efficient-for example, in achieving scale and thereby export performance-although it may entail interaction among a large fraction of players in an industry. The approach that the literature suggests to the application of competition law in small economies places relatively heavy weight on dynamic efficiency as the criterion for competition law design and enforcement. It is squarely in accord with recommendations in the literature on desirable competition law for the so-called new economy.Small; Isolated; Economy; Antitrust; New Zealand; Producer Surplus: Consumer Surplus; Competition Law; Economic Benefit; Economic Detriment; Rule of Reason

1998 Kansas Performance Tests with Sunflower Hybrids

Sunflower performance tests were conducted by the Kansas Agricultural Experiment Station to provide farmers, extension workers, and private industry with unbiased agronomic information on many of the sunflower hybrids marketed in the state. Environmental factors affecting test results and cultural practices are presented for each individual test site

2004 Kansas Performance Tests with Sunflower Hybrids

Sunflower performance tests were conducted by the Kansas Agricultural Experiment Station to provide farmers, extension workers, and private industry with unbiased agronomic information on many of the sunflower hybrids marketed in the state. Environmental factors affecting test results and cultural practices are presented for each individual test site

2007 Kansas Performance Tests with Sunflower Hybrids

Sunflower performance tests were conducted by the Kansas Agricultural Experiment Station to provide farmers, extension workers, and private industry with unbiased agronomic information on many of the sunflower hybrids marketed in the state. Environmental factors affecting test results and cultural practices are presented for each individual test site

Wear Mechanisms in Polyoxymethylene Spur Gears

The interaction of a polymer-steel spur gear pair is naturally prone to cause wear of the softer polymer material. Experimental equipment was therefore designed and constructed to run a polymer-steel spur gear pair with sufficiently accurate instrumentation such that the load and speed could be measured under a range of operating conditions. Plastic deformation features on the polymer teeth surface were observed through scanning electron microscopy and these are considered to be the primary sources of polymer gear wear during service. The wear mechanism is discussed and models are presented to describe the process by which it is created. This is due to the sliding/rolling under conforming contact conditions that are intrinsic to the involute spur gear pair. An iterative model based on the nonlinear properties of the polymer is presented, which shows how the material is deformed permanently and progressively under each load cycle. A second model also shows how the wear deformation features are created. Worn gear teeth were inspected and the quantity of material worn correlates well with the predicted wear volume

Jet-ISM Interaction in the Radio Galaxy 3C293: Jet-driven Shocks Heat ISM to Power X-ray and Molecular H2 emission

We present a 70ks Chandra observation of the radio galaxy 3C293. This galaxy belongs to the class of molecular hydrogen emission galaxies (MOHEGs) that have very luminous emission from warm molecular hydrogen. In radio galaxies, the molecular gas appears to be heated by jet-driven shocks, but exactly how this mechanism works is still poorly understood. With Chandra, we observe X-ray emission from the jets within the host galaxy and along the 100 kpc radio jets. We model the X-ray spectra of the nucleus, the inner jets, and the X-ray features along the extended radio jets. Both the nucleus and the inner jets show evidence of 10^7 K shock-heated gas. The kinetic power of the jets is more than sufficient to heat the X-ray emitting gas within the host galaxy. The thermal X-ray and warm H2 luminosities of 3C293 are similar, indicating similar masses of X-ray hot gas and warm molecular gas. This is consistent with a picture where both derive from a multiphase, shocked interstellar medium (ISM). We find that radio-loud MOHEGs that are not brightest cluster galaxies (BCGs), like 3C293, typically have LH2/LX~1 and MH2/MX~1, whereas MOHEGs that are BCGs have LH2/LX~0.01 and MH2/MX~0.01. The more massive, virialized, hot atmosphere in BCGs overwhelms any direct X-ray emission from current jet-ISM interaction. On the other hand, LH2/LX~1 in the Spiderweb BCG at z=2, which resides in an unvirialized protocluster and hosts a powerful radio source. Over time, jet-ISM interaction may contribute to the establishment of a hot atmosphere in BCGs and other massive elliptical galaxies.Comment: Accepted by ApJ 21 pages in ApJ format, 9 figures, 8 table

Newcomer species from Maltese waters: additions and amendments

The inventory of newcomers in Maltese waters is updated with the addition of 7 alien and 1 range-expanding species, while one previous entry in the inventory is omitted. Thus, a total of 72 alien and 8 range-expanding species have been recorded by February 2016. Half of these species have established populations in Maltese waters while a further 10% are considered to be invasive. The main modes of introduction for alien species in Maltese waters are ‘Shipping’ and ‘Secondary dispersal’ from elsewhere in the Mediterranean. More than half of these newcomer species were recorded since the year 2000.peer-reviewe