Ground Improvement by Deep Vibratory Methods

Vibro compaction and vibro stone columns are the two dynamic methods of soil improvement most commonly used worldwide. These methods have been developed over almost eighty years and are now of unrivalled importance as modern foundation measures. Vibro compaction works on granular soils by densification, and vibro stone columns are used to displace and reinforce fine-grained and cohesive soils by introducing inert material. This second edition includes also a chapter on vibro concrete columns constructed with almost identical depth vibrators. These small diameter concrete piles are increasingly used as ground improvement methods for moderately loaded large spread foundations, although the original soil characteristics are only marginally improved. This practical guide for professional geotechnical engineers and graduate students systematically covers the theoretical basis and design principles behind the methods, the equipment used during their execution, and state of the art procedures for quality assurance and data acquisition. All the chapters are updated in line with recent developments and improvements in the methods and equipment. Fresh case studies from around the world illustrate the wide range of possible applications. The book concludes with variations to methods, evaluates the economic and environmental benefits of the methods, and gives contractual guidance

Ground Improvement by Deep Vibratory Methods

Vibro compaction and vibro stone columns are the two dynamic methods of soil improvement most commonly used worldwide. These methods have been developed over almost eighty years and are now of unrivalled importance as modern foundation measures. Vibro compaction works on granular soils by densification, and vibro stone columns are used to displace and reinforce fine-grained and cohesive soils by introducing inert material. This second edition includes also a chapter on vibro concrete columns constructed with almost identical depth vibrators. These small diameter concrete piles are increasingly used as ground improvement methods for moderately loaded large spread foundations, although the original soil characteristics are only marginally improved. This practical guide for professional geotechnical engineers and graduate students systematically covers the theoretical basis and design principles behind the methods, the equipment used during their execution, and state of the art procedures for quality assurance and data acquisition. All the chapters are updated in line with recent developments and improvements in the methods and equipment. Fresh case studies from around the world illustrate the wide range of possible applications. The book concludes with variations to methods, evaluates the economic and environmental benefits of the methods, and gives contractual guidance

Scattering Theory Approach to Random Schroedinger Operators in One Dimension

Methods from scattering theory are introduced to analyze random Schroedinger operators in one dimension by applying a volume cutoff to the potential. The key ingredient is the Lifshitz-Krein spectral shift function, which is related to the scattering phase by the theorem of Birman and Krein. The spectral shift density is defined as the "thermodynamic limit" of the spectral shift function per unit length of the interaction region. This density is shown to be equal to the difference of the densities of states for the free and the interacting Hamiltonians. Based on this construction, we give a new proof of the Thouless formula. We provide a prescription how to obtain the Lyapunov exponent from the scattering matrix, which suggest a way how to extend this notion to the higher dimensional case. This prescription also allows a characterization of those energies which have vanishing Lyapunov exponent.Comment: 1 figur

A B Cell Receptor with Two Igα Cytoplasmic Domains Supports Development of Mature But Anergic B Cells

B cell receptor (BCR) signaling is mediated through immunoglobulin (Ig)α and Igβ a membrane-bound heterodimer. Igα and Igβ are redundant in their ability to support early B cell development, but their roles in mature B cells have not been defined. To examine the function of Igα–Igβ in mature B cells in vivo we exchanged the cytoplasmic domain of Igα for the cytoplasmic domain of Igβ by gene targeting (Igβc→αc mice). Igβc→αc B cells had lower levels of surface IgM and higher levels of BCR internalization than wild-type B cells. The mutant B cells were able to complete all stages of development and were long lived, but failed to differentiate into B1a cells. In addition, Igβc→αc B cells showed decreased proliferative and Ca2+ responses to BCR stimulation in vitro, and were anergic to T-independent and -dependent antigens in vivo

Cerebral and Extracranial Neurodegeneration are Strongly Coupled in Parkinson’s Disease

In idiopathic Parkinson’s disease (PD), a generalized Lewy body type-degeneration in the brain as well as extracranial organs was identified. It is unclear, whether cerebral and extracranial Lewy body type-degeneration in PD are coupled or not. To address this question, cerebral [123I]FP-CIT SPECT – to quantify cerebral nigrostriatal dopaminergic degeneration – and myocardial [123I]MIBG scintigraphy – to quantify extracranial myocardial sympathetic degeneration – were performed in 95 PD patients and 20 healthy controls. At each Hoehn and Yahr stage separately, myocardial MIBG uptake correlated significantly with striatal FP-CIT uptake. No such correlation was found in the controls. Cerebral and extracranial Lewy body type-degeneration in PD do not develop independently from each other but develop in a strongly coupled manner. Obviously cerebral and extracranial changes are driven by at least similar pathomechanisms. Our findings in controls contradict a physiological correlation between nigrostriatal dopaminergic and myocardial sympathetic function

Radiation enhancement and "temperature" in the collapse regime of gravitational scattering

We generalize the semiclassical treatment of graviton radiation to gravitational scattering at very large energies $\sqrt{s}\gg m_P$ and finite scattering angles $\Theta_s$, so as to approach the collapse regime of impact parameters $b \simeq b_c \sim R\equiv 2G\sqrt{s}$. Our basic tool is the extension of the recently proposed, unified form of radiation to the ACV reduced-action model and to its resummed-eikonal exchange. By superimposing that radiation all-over eikonal scattering, we are able to derive the corresponding (unitary) coherent-state operator. The resulting graviton spectrum, tuned on the gravitational radius $R$, fully agrees with previous calculations for small angles $\Theta_s\ll 1$ but, for sizeable angles $\Theta_s(b)\leq \Theta_c = O(1)$ acquires an exponential cutoff of the large $\omega R$ region, due to energy conservation, so as to emit a finite fraction of the total energy. In the approach-to-collapse regime of $b\to b_c^+$ we find a radiation enhancement due to large tidal forces, so that the whole energy is radiated off, with a large multiplicity $\langle N \rangle\sim Gs \gg 1$ and a well-defined frequency cutoff of order $R^{-1}$. The latter corresponds to the Hawking temperature for a black hole of mass notably smaller than $\sqrt{s}$.Comment: 5 pages, 2 figures, talk presented at the European Physical Society Conference on High Energy Physics, 5-12 July, Venice, Ital

Eigenvalue bounds in the gaps of Schrodinger operators and Jacobi matrices

We consider $C=A+B$ where $A$ is selfadjoint with a gap $(a,b)$ in its spectrum and $B$ is (relatively) compact. We prove a general result allowing $B$ of indefinite sign and apply it to obtain a $(\delta V)^{d/2}$ bound for perturbations of suitable periodic Schrodinger operators and a (not quite)Lieb-Thirring bound for perturbations of algebro-geometric almost periodic Jacobi matrices

Chemical and Enzymatic Synthesis of Sialylated Glycoforms of Human Erythropoietin

Recombinant human erythropoietin (EPO) is the main therapeutic glycoprotein for the treatment of anemia in cancer and kidney patients. The in‐vivo activity of EPO is carbohydrate‐dependent with the number of sialic acid residues regulating its circulatory half‐life. EPO carries three N‐glycans and thus obtaining pure glycoforms provides a major challenge. We have developed a robust and reproducible chemoenzymatic approach to glycoforms of EPO with and without sialic acids. EPO was assembled by sequential native chemical ligation of two peptide and three glycopeptide segments. The glycopeptides were obtained by pseudoproline‐assisted Lansbury aspartylation. Enzymatic introduction of the sialic acids was readily accomplished at the level of the glycopeptide segments but even more efficiently on the refolded glycoprotein. Biological recognition of the synthetic EPOs was shown by formation of 1:1 complexes with recombinant EPO receptor

Loss of ceramide synthase 3 causes lethal skin barrier disruption

The stratum corneum as the outermost epidermal layer protects against exsiccation and infection. Both the underlying cornified envelope (CE) and the intercellular lipid matrix contribute essentially to these two main protective barriers. Epidermis-unique ceramides with ultra-long-chain acyl moities (ULC-Cers) are key components of extracellular lipid lamellae (ELL) and are bound to CE proteins, thereby contributing to the cornified lipid envelope (CLE). Here, we identified human and mouse ceramide synthase 3 (CerS3), among CerS1-6, to be exclusively required for the ULC-Cer synthesis in vitro and of mouse CerS3 in vivo. Deficiency of CerS3 in mice results in complete loss of ULC-Cers (≥C26), lack of continuous ELL and a non-functional CLE. Consequently, newborn mutant mice die shortly after birth from transepidermal water loss. Mutant skin is prone to Candida albicans infection highlighting ULC-Cers to be pivotal for both barrier functions. Persistent periderm, hyperkeratosis and deficient cornification are hallmarks of mutant skin demonstrating loss of Cers to trigger a keratinocyte maturation arrest at an embryonic pre-barrier stag