Some myxomycetes from the Baix Empordà region, Catalonia, Spain

During a collecting trip in July–August 2002 and a few additional visits to the Baix Empordà region, province of Gerona, Catalonia, Spain, 26 species of myxomycetes were found. Two species, Stemonaria fuscoides Nann.-Brem. et Y. Yamam. and Stemonitopsis subcaespitosa (Peck) Nann.-Brem., have not been recorded in Spain before. The species collected are listed and a number of the more interesting species are illustrated and discussed in more detail

Geology and palaeontology of a temporary exposure of the late Miocene Deurne sand in Antwerpen (N.Belgium)

A section of 6.10 m through the Deurne Sand Member (Diest Formation, Late Miocene) in Antwerpen (Antwerp) is described, which has been observed during the construction works of a new hospital building in the southern part of Deurne, and here called “Middelares Hospital Section” after that location. This temporary outcrop section can well be correlated with a similar one which was outcropping some 35 years ago, and was located at some 1.5 km to the NE. It was studied in detail by De Meuter et al. (1967), who called it the “Borgerhout-Rivierenhof VII B.R.” section. Since that section was the most relevant of the previously described sections in the Deurne Sand Member, it is here suggested to designate that section as stratotype for the member. Part of the fossil content, mainly the macrofossils (Brachiopoda, Mollusca, Ostracoda, Thoracica, Pisces, Reptilia and Mammalia) is listed. Two species of Terebratulidae (Pliothyrina sowerbyana (Nyst, 1843) and Terebratula cf. ampulla Brocchi, 1814) were recognized. The Mollusca are represented by 24 taxa, of which the Pectinidae are the most common. One undescribed ostracod taxon (Thaerocythere sp.) is restricted to the Deurne Sands and can be considered a stratigraphic marker for this member. Fossil Lepadomorpha are recorded for the first time from the Belgian Late Miocene. The Squalus sp. from the Deurne Sands closely resembles the Squalus sp. from the Gramian of Denmark. Preliminary data about a fairly complete skeleton of a Mysticete whale, probably belonging to the genus Plesiocetus Van Beneden (in Van Beneden & Gervais, 1880) are given. The recovered specimen of Ziphirostrum is characteristic of Z. laevigatum and is probably different from Z. belgicus. The molluscan fauna seems to point to a shallow environment with swiftly changing currents, moving sand bars or megaripples subjected to tidal currents. Palaeoclimatological data cannot be deducted from the fossils encountered

A leatherback turtle (Testudines, Dermochelyidae) from the Miocene of the Westerschelde, the Netherlands

The Westerschelde Estuary in The Netherlands is known for its rich vertebrate fossil content. In a recent trawling campaign aimed at sampling a late Miocene marine vertebrate assemblage, over 5000 specimens were retrieved, all currently stored in the Natuurhistorisch Museum Rotterdam. One specimen is a well preserved fragment of a dermochelyid sea-turtle carapace. The Westerschelde specimen is an addition to the scant hypodigm of dermochelyids from the Miocene North Sea. The carapace fragment is described and identified as Psephophorus polygonus. The various secondary marks present on the fragment are suggestive of both predatory and scavenging origin. Based on the assumption that P. polygonus had a similar carapace structure as recent D. coriacea, the minimal size of the complete carapace is estimated to have been 168 x 126 cm. Furthermore, based on the physical traits of the Westerschelde specimen and a reexamination of P. polygonus specimens, including the neotype stored at the Naturhistorisches Museum Wien (Austria), it is argued that previously assigned characteristics cannot be used as discriminative taxonomic properties of dermochelyids in general, and of P. polygonus in particular. An improved cladistic analysis on dermochelyids is performed based on previously defined and new taxonomic characters. Using this analysis it is argued that Psephophorus calvertensis is a junior synonym of P. polygonus. Hence, a new diagnosis of Psephophorus polygonus is defined. The ‘addition’ of P. calvertensis to the species P. polygonus confirms its presence on both sides of the Atlantic Ocean. Therefore, we suggest P. polygonus to have had a cosmopolitan distribution, similar to the extant species Dermochelys coriacea

A new Oligocene site with terrestrial mammals and a selachian fauna from Minqar Tibaghbagh, the western Desert of Egypt

A new fossil site at Minqar Tibaghbagh, east of Siwa, in the Egyptian Western Desert is described. This represents the first place in Egypt outside the Fayum Depression yielding Paleogene, terrestrial mammals. Initial studies indicate the presence of palaeomastodonts, hyracoids, and anthracotheres, presumably early Oligocene in age. As only surface prospecting has been performed, more taxa will almost certainly be discovered in future investigations here and probably also elsewhere in the surroundings. A comparison is made with the most important contemporaneous sites in Libya and Egypt that yield terrestrial mammal remains. The selachian fauna from a higher level in the section confirms the Paleogene age of the subjacent strata. It is compared with selachians faunas from the early Oligocene Eastern Tethys Ocean at other places (the Fayum Depression in Egypt, and sites in Oman and Pakistan), and differs from these sites in being fully marine. Contrary to earlier studies, the open marine mudstones of the Daba’a Formation at Minqar Tibaghbagh are overlain by Paleogene marine sediments of most probably early Oligocene age and not early Miocene marine sediments as previously reported. These strata represent not only a new site with great potential for future finds, but also allows for biostratigraphic correlation

The dynamics of human body weight change

An imbalance between energy intake and energy expenditure will lead to a change in body weight (mass) and body composition (fat and lean masses). A quantitative understanding of the processes involved, which currently remains lacking, will be useful in determining the etiology and treatment of obesity and other conditions resulting from prolonged energy imbalance. Here, we show that the long-term dynamics of human weight change can be captured by a mathematical model of the macronutrient flux balances and all previous models are special cases of this model. We show that the generic dynamical behavior of body composition for a clamped diet can be divided into two classes. In the first class, the body composition and mass are determined uniquely. In the second class, the body composition can exist at an infinite number of possible states. Surprisingly, perturbations of dietary energy intake or energy expenditure can give identical responses in both model classes and existing data are insufficient to distinguish between these two possibilities. However, this distinction is important for the efficacy of clinical interventions that alter body composition and mass

Side channel analysis of some hash based MACs:A response to SHA-3 requirements

The forthcoming NIST's Advanced Hash Standard (AHS) competition to select SHA-3 hash function requires that each candidate hash function submission must have at least one construction to support FIPS 198 HMAC application. As part of its evaluation, NIST is aiming to select either a candidate hash function which is more resistant to known side channel attacks (SCA) when plugged into HMAC, or that has an alternative MAC mode which is more resistant to known SCA than the other submitted alternatives. In response to this, we perform differential power analysis (DPA) on the possible smart card implementations of some of the recently proposed MAC alternatives to NMAC (a fully analyzed variant of HMAC) and HMAC algorithms and NMAC/HMAC versions of some recently proposed hash and compression function modes. We show that the recently proposed BNMAC and KMDP MAC schemes are even weaker than NMAC/HMAC against the DPA attacks, whereas multi-lane NMAC, EMD MAC and the keyed wide-pipe hash have similar security to NMAC against the DPA attacks. Our DPA attacks do not work on the NMAC setting of MDC-2, Grindahl and MAME compression functions. This talk outlines our results

Some myxomycetes from the Baix Empordà region, Catalonia, Spain

During a collecting trip in July–August 2002 and a few additional visits to the Baix Empordà region, province of Gerona, Catalonia, Spain, 26 species of myxomycetes were found. Two species, Stemonaria fuscoides Nann.-Brem. et Y. Yamam. and Stemonitopsis subcaespitosa (Peck) Nann.-Brem., have not been recorded in Spain before. The species collected are listed and a number of the more interesting species are illustrated and discussed in more detail