Hammett Correlations in the \u3csup\u3e1\u3c/sup\u3eH NMR Spectra of Some N-Arlydihalonicotinamides

Excellent linear correlations of amide proton chemical shifts (Snh) (in DMSO-d6 ) with Hammett substituent constants (5) for a series of 4-substituted anilides of four dihalonicotinic acid systems were observed. Dihalonicotinanilides with chlorine in the pyridine 2 - position exhibited a more positive slope in a Hammett plot of S^H vs - aR- where R is the substituent in the 4 position of the benzene ring. This observation is explained in terms of the inductive effect of chlorine which results in a slightly more acidic amide proton, which in turn causes an enhanced hydrogen bonding tendency to solvent. Four disubstituted anilides were also prepared, and the 5NH of these derivatives correlated well with the additive value of the 6R\u27s of the two substituents

Distal subgaleal-peritoneal shunt migration into the abdominal wall with subsequent formation of a pre-peritoneal pseudocyst: a rare complication.

Distal ventriculo-peritoneal shunt migration and extra-peritoneal CSF pseudocyst formation are unusual complications of shunt placement. We present a 65-year-old-female who received a subgaleal-peritoneal shunt to decompress a post-surgical subgaleal fluid collection. Eight weeks later, shunt series showed tight coiling of the distal catheter, and operative exploration found the distal shunt tip to have migrated superficial to the rectus sheath, where it had become encapsulated in a pre-peritoneal CSF pseudocyst. Migration of the distal catheter into the abdominal wall was likely due to local inflammation of the inner surface of the abdomen, with pressure from intestinal peristaltic movements and intra-abdominal pressure, and continued inflammation at the distal catheter tip may have caused formation of a pre-peritoneal CSF pseudocystic dilatation. To date, this is the first reported case of distal shunt migration into the abdominal wall with subsequent formation of an extra-peritoneal pseudocyst and represents a rare event in the surgical management of peritoneal shunts

Detecting Dark Matter Annihilation with CMB Polarization : Signatures and Experimental Prospects

Dark matter (DM) annihilation during hydrogen recombination (z ~ 1000) will alter the recombination history of the Universe, and affect the observed CMB temperature and polarization fluctuations. Unlike other astrophysical probes of DM, this is free of the significant uncertainties in modelling galactic physics, and provides a method to detect and constrain the cosmological abundances of these particles. We parametrize the effect of DM annihilation as an injection of ionizing energy at a rate e_{dm}, and argue that this simple "on the spot'' modification is a good approximation to the complicated interaction of the annihilation products with the photon-electron plasma. Generic models of DM do not change the redshift of recombination, but change the residual ionization after recombination. This broadens the surface of last scattering, suppressing the temperature fluctuations and enhancing the polarization fluctuations. We use the temperature and polarization angular power spectra to measure these deviations from the standard recombination history, and therefore, indirectly probe DM annihilation. (abridged)Comment: 13 pages, 8 figures, submitted to PR

Positive Geometries for all Scalar Theories from Twisted Intersection Theory

We show that accordiohedra furnish polytopes which encode amplitudes for all massive scalar field theories with generic interactions. This is done by deriving integral formulae for the Feynman diagrams at tree level and integrands at one loop level in the planar limit using the twisted intersection theory of convex realizations of the accordiohedron polytopes.Comment: v2: Corrected typos and added references - published versio

Some remarks on hypergraph matching and the F\"{u}redi-Kahn-Seymour conjecture

A classic conjecture of F\"{u}redi, Kahn and Seymour (1993) states that given any hypergraph with non-negative edge weights $w(e)$, there exists a matching $M$ such that $\sum_{e \in M} (|e|-1+1/|e|)\, w(e) \geq w^*$, where $w^*$ is the value of an optimum fractional matching. We show the conjecture is true for rank-3 hypergraphs, and is achieved by a natural iterated rounding algorithm. While the general conjecture remains open, we give several new improved bounds. In particular, we show that the iterated rounding algorithm gives $\sum_{e \in M} (|e|-\delta(e))\, w(e) \geq w^*$, where $\delta(e) = |e|/(|e|^2+|e|-1)$, improving upon the baseline guarantee of $\sum_{e \in M} |e|\,w(e) \geq w^*$

Efficiency of S&P CNX Nifty Index Option of the National Stock Exchange (NSE), India, using Box Spread Arbitrage Strategy

Box spread is a trading strategy in which one simultaneously buys and sells options having the same underlying asset and time to expiration, but different exercise prices. This study examined the efficiency of European style S&P CNX Nifty Index options of National Stock Exchange, (NSE) India by making use of high-frequency data on put and call options written on Nifty (Time-stamped transactions data) for the time period between 1st January 2002 and 31st December 2005 using box-spread arbitrage strategy. The advantages of box-spreads include reduced joint hypothesis problem since there is no consideration of pricing model or market equilibrium, no consideration of inter-market non-synchronicity since trading box spreads involve only one market, computational simplicity with less chances of mis-specification error, estimation error and the fact that buying and selling box spreads more or less replicates risk-free lending and borrowing. One thousand three hundreds and fifty eight exercisable box-spreads were found for the time period considered of which 78 Box spreads were found to be profitable after incorporating transaction costs (32 profitable box spreads were identified for the year 2002, 19 in 2003, 14 in 2004 and 13 in 2005) The results of our study suggest that internal option market efficiency has improved over the years for S&P CNX Nifty Index options of NSE India.    

Home Energy Efficiency and Mortgage Risks: Research funded by the Institute for Market Transformation

Many have theorized that energy efficient homes should have lower default risks than standard homes because the former are associated with lower energy costs, which leaves more money to make the mortgage payment. However, few empirical studies have been conducted due to limited data availability. This study examines actual loan performance data obtained from CoreLogic, the lending industry's leading source of such data. To assess whether residential energy efficiency is associated with lower default and prepayment risks, a national sample of about 71,000 ENERGY STAR- and non-ENERGY STAR-rated single-family home mortgages was carefully constructed, accounting for loan, household, and neighborhood characteristics.The study finds that default risks are on average 32 percent lower in energy-efficient homes, controlling for other loan determinants. This finding is robust, significant, and consistent across several model specifications. A borrower in an ENERGY STAR residence is also one-quarter less likely to prepay the mortgage. Within ENERGY STAR-rated homes, default risk is lower for more energy-efficient homes. The lower risks associated with energy efficiency should be taken into consideration when underwriting mortgages

4-Substituted Anilides of 2,6- and 5,6- Dichlorolicotinic Acid. Potential Agricultural Agents

A series of 4-substituted anilides of 2,6- and 5,6 dichloronicotinic acid were prepared. The acids were first converted to their acid chlorides, which were in turn treated with the appropriate 4-substituted aniline in chloroform. A total of 16 anilides was thus prepared, and their structures confirmed. These compounds were prepared for testing as possible herbicidal, pesticidal or fungicidal agent

Decentralised Service Allocation using Blockchain

The growing demand for short-term property renting has led to the boom of a new category called PropTech (Property + Technology). Such a rise in demand attracted many entrepreneurs and investors leading to the inception of powerful and centralised players in the category (like Airbnb). Unfortunately, some big players are controlling the entire industry in a centralised way in turn, performing anti-competitive practices which leave no room for the small players. Such an ecosystem can be made more transparent and decentralised by executing transactions and order-fulfilment on a blockchain. To extend the functionality of the system, we can also perform the renting of small services and appliances via the integration of IoT. Implementing such a system will make the process more transparent, robust and decentralised.Comment: 5 page