A redescription of Paralimnadia urukhai Webb and Bell 1979 with the description of a new species P. minyspinosa (Crustacea: Branchiopoda: Limnadiidae).

Clam shrimps of the genus Paralimnadia living in small pools of the eastern highlands are particularly variable between populations. A detailed study of many populations of P. urukhai in the northern New England Tablelands revealed almost random variation in normally conservative characters such as egg morphology and cercopod setae as well as wide variation in other less defining characters. This necessitates a revised description of this species. This redescription focuses only on the Stanthorpe group of populations as previous genetic analysis suggests the Bald Rock populations could represent a separate species, but the two cannot be separated presently based on morphological features. However, two populations 100 km to the south are morphologically and genetically distinct enough to constitute a new species which we describe herein. All these populations live in isolated rock pools within forests where dispersal is difficult, so that retained founder effects and local adaptation are probably directing interpopulation variability

Time-Dependent Alignment of Molecules Trapped in Octahedral Crystal Fields

The hindered rotational states of molecules confined in crystal fields of octahedral symmetry, and their time-dependent alignment obtained by pulsed nonresonant laser fields, are studied computationally. The control over the molecular axis direction is discussed based on the evolution of the rotational wave packet generated in the cubic crystal-field potential. The alignment degree obtained in a cooperative case, where the alignment field is applied in a favorable crystal-field direction, or in a competitive direction, where the crystal field has a local maximum, is presented. The investigation is divided into two time regimes where the pulse duration is either ultrashort, leading to nonadiabatic dynamics, or long with respect to period of molecular libration, which leads to synchronous alignment due to nearly adiabatic following. The results are contrasted to existing gas phase studies. In particular, the irregularity of the crystal field energies leads to persistent interference patterns in the alignment signals. The use of nonadiabatic alignment for interrogation of crystal-field energetics and the use of adiabatic alignment for directional control of molecular dynamics in solids are proposed as practical applications

Aligning and Orienting Molecules Trapped in Octahedral Crystal Fields

The effect of external fields on directional states of a linear molecule trapped in a crystal field of octahedral symmetry is studied numerically. Adiabatic field-dressed energy levels are obtained by solving the time-independent Schrödinger equation for the rotational degrees of freedom of the confined molecule. In the absence of external fields, the internal, octahedral crystal field serves to transform free-rotor states to angularly confined librational states of defined parity which arrange in near-degenerate sets of high multiplicity. Interaction of a linearly polarized, nonresonant laser field with the polarizability or of a static electric field with the dipole moment create alignment or orientation of the molecular axis, respectively. In the latter case, the combined effect of internal (octahedral) and external static field is instrumental in creating orientation by coupling different tunneling states. Depending on the polarization direction of the external fields with respect to the symmetry axes provided by the crystal field, cooperative and competitive effects are distinguished. If the direction of the external field coincides with the minima of the crystal field, high degrees of alignment or orientation can be achieved for specific states, even for low field strengths. Otherwise, high efficiency of this mechanism is restricted to high fields and low temperatures. Strategies for an experimental realization are outlined

Laser-induced alignment and anti-alignment of rotationally excited molecules

We numerically investigate the post-pulse alignment of rotationally excited diatomic molecules upon nonresonant interaction with a linearly polarized laser pulse. In addition to the simulations, we develop a simple model which qualitatively describes the shape and amplitude of post-pulse alignment induced by a laser pulse of moderate power density. In our treatment we take into account that molecules in rotationally excited states can interact with a laser pulse not only by absorbing energy but also by stimulated emission. The extent to which these processes are present in the interaction depends, on the one hand, on the directionality of the molecular angular momentum (given by the M quantum number), and on the other hand on the ratio of transition frequencies and pulse duration (determined by the J number). A rotational wave packet created by a strong pulse from an initially pure state contains a broad range of rotational levels, over which the character of the interaction can change from non-adiabatic to adiabatic. Depending on the laser pulse duration and amplitude, the transition from the non-adiabatic to the adiabatic limit proceeds through a region with dominant rotational heating, or alignment, for short pulses and a large region with rotational cooling, and correspondingly preferred anti-alignment, for longer pulses

Intense-Field Alignment of Molecules Confined in Octahedral Field

The combined effect of static octahedral potential and anisotropic interaction with intense linearly polarized light on the rotational motion of linear molecules is investigated. Avoided crossings of quantized energy levels corresponding to pendular states with different degree of alignment are found by varying the strength parameters for the light and static fields. High alignment is achieved for both co-operative and competitive choices of the relative directionality of the two fields, thus presenting means for controlling dynamics of impurity centers with respect to the surrounding media

State Selection in Non-Resonantly Excited Wave Packets by Tuning from Non-Adiabatic to Adiabatic Interaction

We show for rotational alignment of diatomic molecules that the crossover from non-adiabatic to adiabatic limits is well described by a convolution of excitation pulse envelope and sinusoidal molecular response and that it takes place in a uniform way in the region between 0.1 and 1 for the ratio of pulse duration to rotational period. In a non-resonant Raman-type excitation, this crossover is used to manipulate the J composition of a rotational wave packet with respect to the initial thermal distribution. By optimizing the duration of a single pulse, arbitrarily narrow distributions at low J levels can be formed. A double pulse excitation, where a longer second pulse acts as a selective dump pulse, allows to prepare non-thermal distributions centered at high J values. With the alignment signal on top of an isotropic background, experimental techniques sensitive to the induced anisotropy are optimally suited for implementation. To demonstrate the efficiency of the method, numerical simulations are carried out for rotational alignment in 14N2 at various experimentally relevant laser intensities. The scheme is transferable to quantum systems with a significant variation of transition frequencies between subsequent levels

Vibrational Overtones and Rotational Structures of HCl in Rare Gas Matrices

The rotational structure in the vibrational transitions from ν=0 to ν=1,2,3,4 of H35Cl and H37Cl is studied in Xe, Kr and Ar matrices with high spectral resolution. A consistent set of rotational constants Bv for the vibrational levels ν=0 to 4 is derived. B0 decreases with the tightness of the cage from 9.78 cm-1 in Xe to 8.83 cm-1 in Ar for H35Cl (gas phase 10.44 cm-1). The values for B0 to B4 decrease linearly with v due to the vibration-rotation-coupling constant α which increases from 0.37 cm-1 in Xe to 0.479 cm-1 in Ar (gas 0.303) according to the cage tightness. The splitting of the R(1) transition which originates from the hindering of rotation is analyzed in Xe using the T2g-T1u and T2g-Eg transition energies. A comparison with force field calculations yields a dominant contribution of the 6th spherical harmonic YA1g6 of the octahedral matrix potential. The modulation of the potential takes a value of K6/B=17 which corresponds to a barrier for the rotation of 160 cm-1. The splitting increases with the vibrational level v which can be interpreted as a weak admixture of the YA1g4 spherical harmonic. A large isotope effect and a reduction of the T1u-A1g transition energy (R(0)-transition) beyond the crystal field value are attributed to an excentric rotation with a displacement of the center of mass of the order of 0.05 Å. The vibrational energies ωe show an opposite trend with matrix atom size and decrease with polarizability from 2970 cm-1 in Ar to 2945.4 cm-1 in Xe (gas 2989.9 cm-1) while the anharmonicity ωeχe of the free molecule lies close to the Kr value and thus between that of Ar and Xe

Unusual Differential Diagnosis of Upper Abdominal Pain

We here present an interesting unusual case of upper abdominal pain. The patient was a 38-year-old man, who was admitted to our hospital complaining of right upper quadrant pain caused by a toothpick that perforated the anterior gastric wall and penetrated segment I of the liver. After endoscopic removal and an initially uneventful course, computed tomography revealed a perigastric abscess that was treated by repeated gastroscopic rinsing via an endoscopically placed catheter. After another three uneventful weeks, a liver abscess with minor tendency to constrict the portal vein was diagnosed, and a segment I liver resection together with abscess drainage was performed. The peculiarity of this case is the rarity of toothpick ingestion and gastric perforation in a young and healthy white Caucasian followed by development of a liver abscess after primary uneventful endoscopic removal. In light of this case, gastric perforation due to ingested foreign bodies such as toothpicks can be considered a rare cause of upper abdominal pain

Molecular mechanisms of transcriptional repression by the EWS-FLI1 oncogene in Ewing’s Sarcoma

Ewing-Sarkome sind die am zweithäufigsten auftretenden Knochen- und Weichteil-tumore bei Kindern. Sie sind klein-rund-blauzellige Tumore, die hohe Spiegel des Zelloberflächen-Glykoproteins CD99 exprimieren und sich durch die t(11;22) (q24;q12) Translokation auszeichnen. Diese führt zum EWS-FLI1 Fusionsgen, welches in 85% aller Tumore der Ewing-Sarkom Familie gefunden werden kann. Mittels der Affymetrix Gen Chip Technologie analysierte unser Labor die Gen-expression von sechs Ewing-Sarkom-Zelllinien und fand 73 überexprimierte Gene und 52 Gene mit verringerter Expression. Diese Daten legen nahe, dass EWS-FLI1 nicht nur als transkriptionaler Aktivator, sondern auch als Repressor funktioniert. Unter den reprimierten Genen fanden wir den Notch-Liganden JAG1, das Notch-Zielgen Hey1 und den Zellzyklus-Inhibitor p21. Die direkte Reprimierung von p21 durch die Bindung von EWS-FLI1 an putative ETS Motive wurde bereits publiziert. p21 arretiert den Zellzyklus in der G1-Phase nach der Aktivierung von p53. In den 10kb der p21-Promoter-Region sind mehrere p53 und Ets Bindungsmotive zu finden, aber nur an zwei Stellen beide innerhalb weniger Nukleotide. Wir beschreiben hier erstmalig eine Genreporteranalyse von 14 Genreporterkonstrukten, welche in überlappenden Fragmenten 10kb der p21-Promoter-Region abdecken. EWS-FLI1 Knock-down resultierte in erhöhter Expression von p21 in den beiden p53 und Ets enthaltenden Konstrukten, in einer p53wt Ewing-Sarkom-Zelllinie, nicht aber in einer Zelllinie mit mutiertem p53. Induktion von p53 und Knock-down von EWS-FLI1 erhöhte die Expression von p21 noch stärker, während ein Knock-down von p53 p21 verringerte. Diese Daten legen nahe, dass p53 in die Genregulation von p21 durch EWS-FLI1 involviert ist. EWS-FLI1 Knock-down resultierte in einer erhöhten Expression von JAG1 in Reporter Gen Assays mit zwei JAG1-Konstrukten, die 1.7kb bzw. 573bp der JAG1-Promoter-Region enthalten. Unsere Daten lassen vermuten, dass sich das regulatorische Element für die Repression von JAG1 in den 573bp befindet. EWS-FLI1 Knock-down führte zu erhöhter Expression von Hey1 in Reporter Gen Assays mit zwei Hey1-Konstrukten, die 3.9kb bzw. 1.7kb der Hey1-Promoter-Region beinhalten. Unsere Daten deuten darauf hin, dass für die Repression von Hey1 durch EWS-FLI1 die 3.9kb Sequenz notwendig ist. Wir konnten in dieser Arbeit zeigen, dass EWS-FLI1 als transkriptionaler Repressor, nicht nur p21, sondern auch die Notch-Signalübertragungsweg Komponenten JAG1 und Hey1 reprimiert.Ewing’s sarcoma is the second most common bone and soft tissue cancer in children with an occurrence of 1-3 cases in 1 million people. Ewing’s sarcoma are small round blue cell tumors that express high levels of the cell surface glycoprotein CD99 and carry the t(11;22) (q24;q12) translocation. This generates the EWS-FLI1 fusion gene which can be found in 85% of all Ewing’s sarcoma family tumors. Using Affymetrix gene chip technology, our lab had analyzed the gene expression in six Ewing’s sarcoma cell lines and found 73 overexpressed genes and 52 genes repressed by EWS-FLI1. These data indicate that EWS-FLI1 may act not only as transcriptional activator, but also as a transcriptional repressor. Among these repressed genes we found, the Notch ligand JAG1, the Notch target Hey1 and the cell cycle inhibitor p21. It has already been published, that p21 is directly repressed by EWS-FLI1 by binding to a putative Ets motif within the p21 promoter. p21 is a cyclin-dependent kinase inhibitor, and as a direct target of p53, it arrests the cell cycle in G1 after activation of p53. Several p53 and Ets binding motifs are distributed over 10kb of the p21 5’ flanking sequence, but remarkably there are two sites where both, p53 and Ets motifs were found in a cluster. We describe here for the first time a gene reporter analysis of 14 reporter gene constructs which contain overlapping parts covering 10kb of the p21 promoter region. shRNA mediated knock down of EWS-FLI1 resulted in the upregulation of p21 in those two constructs which contain both Ets and p53 binding sites in a p53wt Ewing’s sarcoma cell line, but not in a p53mut cell line. Induction of p53 via Etoposide treatment and knock down of EWS-FLI1 resulted in even higher induction of those two constructs in the p53wt cell line, whereas knock down of p53 reduced them. These data indicate strongly that p53 is involved in the gene expression regulation of p21 by EWS-FLI1. Reporter gene assays using two JAG1 constructs encoding for 1.7kb and 573bp of the JAG1 promoter region resulted in an induction for both constructs upon knock down of EWS-FLI1 in several cell lines. Our data indicate that the regulatory element responsible for the repression of JAG1 by EWS-FLI1 is within the 573bp. Knock down of EWS-FLI1 resulted in an induction of Hey1 in reporter gene assays using two constructs encoding for 3.9kb and 1.7kb of the Hey1 promoter region. Our data suggest that the 3.9kb sequence is necessary for full repression by EWS-FLI1. We could demonstrate here that EWS-FLI1 acts as a transcriptional repressor, not only for p21, but as well for the Notch pathway components JAG1 and Hey1